McMillan herself has become a publishing phenomenon by telling just such other stories, about present-day, urban African-Americans who have left the "ghetto" behind. Her upwardly mobile women reflect a post-civil rights reality, which was won through integration and higher education. As McMillan once remonstrated with an editor who thought that the voice of Zora, the schoolteacher in her second novel, Disappearing Acts (1989), was too "preppy" - "Look, she's not barefoot and pregnant, living in the projects and getting her ass kicked. I cannot apologise because some of us have been to college."

Her third novel, Waiting To Exhale (1992), was her big breakthrough. The tale of four professional women, with everything in life but a good man, sold some four million copies, and won her the second-largest advance, of $2.6m, then paid for a novel's paperback rights (after Scott Turow's $3.3m for Presumed Innocent). It spawned leagues of imitators, and a sub-genre of "girlfriend fiction", while book clubs, or "sister circles", mushroomed and McMillan's readings needed crowd control. A revolution was born when, as she says, "publishers took note that black people do read, and that other ethnic groups will read books about black people". What the New York Times dubbed the "Terry McMillan effect" rippled through the industry, from policy on hiring editors to new black fiction imprints.

Waiting To Exhale's Hollywood incarnation in 1996 as the first "black chick-flick", starring Whitney Houston, Angela Bassett and Wesley Snipes, broke more ground as a "crossover" success, grossing $67m at the US box office. It helped spur more films that abandoned the 'hood for the hearth, such as Soul Food and The Best Man. McMillan's next novel, How Stella Got Her Groove Back (1996), which secured her a staggering $6m advance, became an instant bestseller and another Hollywood film, this time starring Angela Bassett, Taye Diggs and Whoopi Goldberg. McMillan was executive producer and co-writer of both films, and of last year's US TV film of Disappearing Acts, starring Wesley Snipes and Sanaa Lathan.

Her success has made her a target, however. She has been attacked for caricaturing black men as irresponsible losers; for depicting professional black women as shopaholic airheads pining for romance - or a shag; for characters who are too conspicuous in their brand-name consumption, or too assimilated. Publishers Weekly dubbed her the "Judith Krantz of the black bourgeoisie", after the queen of airport sex-and-shopping fodder. Yet, although her fiction may have such elements, its ebullient wit and sass, the social problems she airs - from incest to alcoholism - and the "homegirl" voice her characters slip in and out of, make it less easy to categorise or dismiss. While the shopping sprees and six-figure salaries in her fiction have drawn accusations of fairytale wish-fulfilment, McMillan peddles no dreams she has not herself realised. The milieu of her novels has risen with her own standing, just as they mirror an emotional evolution in her life.

At home in Danville, a suburb 40 miles east of San Francisco, McMillan appears at ease both with herself and with the success she has earned. At 49, she retains a taste for straight-talking and loud colours, in lime-green trousers and multicoloured top, russet dreadlocks pulled high on her head. But there are signs of embattlement. There may be an edge of snobbery in criticism of her nouveau riche characters, however sophisticated their taste, whose financial ease is hard-earned enough for it still to be a source of satisfaction. Resentful of a media focus on the size of her house - or "mansion", as some would have it - McMillan attributes much of the sneering to a backlash against success, especially for someone who is "black and/or a woman".

As she spells it out: "It's like, don't hate me because I'm beautiful - ya hear what I'm saying?" Her new novel, A Day Late And A Dollar Short, is a departure from the "girlfriend" and "relationship" fiction of her past three books, and a return to the family-centred drama of her first, Mama (1987). She began it eight years ago, as a picture of a "family who missed the boat sometimes". "It was a time when it seemed things were happening out of sync," she explains. "Old lovers resurfaced and wanted to pick up where they thought they'd left off.

It was hilarious; some people have no sense of timing." But it made her ponder what she would do differently with hindsight. "We take a lot of things for granted - especially when it comes to family."

The book came to a standstill, however, when her mother died suddenly of an asthma attack in September 1993, while McMillan was on a book tour in Italy. "I went numb," she says. "She was 59 years old.

I never knew her asthma was as bad as it was." Then, almost exactly a year later, her best friend died of liver cancer. It was the day McMillan had planned to quit smoking, and she kept her vow. "My girlfriend had said, 'You better, too, bitch', and even though she died, me smoking wouldn't have brought her back." She visited Jamaica in 1995. "I was tired of being sad. Out of boredom I decided to take a vacation, to see if I myself hadn't died; I felt like a piece of rubber." The outcome is known to her fans through the novel that emerged, How Stella Got Her Groove Back.

Like her 40-something heroine, McMillan returned home with a Jamaican man in his 20s, Jonathan Plummer, whom she married in September 1998. Plummer, a pet groomer who spruces up Californian loved ones, keeps 40 birds and a 250-gallon reef tank full of fish in the house they share with her son Solomon. Seventeen last month, Solomon is a 6ft 2in track runner and prospective student whose photographs adorn his mother's office walls.

The next year, McMillan returned to work on A Day Late And A Dollar Short, which is dedicated to her mother, Madeline, and her four younger siblings, Edwin, Rosalyn, Crystal and Vicky. The Price family of the book have aspects of her own: Viola is the asthmatic mother of four grown-up children, while the sole brother has suffered arthritis and brushes with the law. The eldest daughter, Paris, a Danville upmarket caterer, is "patterned after" McMillan, though with problems the author does not have, such as a teenage son who may have got his girlfriend pregnant. "I hope I wasn't prophesying. As far as I know, my son's not sexually active," she says with a tone suggesting he better not be.

The novel is driven by the dynamics of birth order. "There's a lot of truth in it," she says. While she feels that the baby in large families is "sometimes lazier; they don't always have the same ambition", it is the middle child who spurs rivalry. "I have a sister who doesn't speak to me from one year to the next," says McMillan, "but I was very kind in the rendering. I didn't give Charlotte in the novel quite the traits my sister has. When you're a middle child, if you feel neglected, you can end up with a lot of resentment. In this case, there's envy and jealously. There is in a lot of families."

Rosalyn McMillan followed her eldest sister into print, with a debut novel, Knowing (1996), four years after Waiting To Exhale, and later Blue Collar Blues (1998) and The Flip Side Of Sin (2000). Terry chooses her words on the matter with care: "First, I've never seen any writer as a rival." She gestures at her shelves and evokes another book-filled house on Lake Tahoe. "I love what writers do, and I've promised never to say anything bad about any writer, especially a black writer, and especially my sister. But it's kind of obvious why she started writing. I've always wanted the best for her. But the kind of stories she tells, and how she tells them, I'm not fond of. She chose this medium to make a point: that she can do what I do. I never doubted her worth as a human being; I've always loved her. Her writing books won't prove anything to me." Writing her new novel taught McMillan something about herself. "I had to admit, I am a control freak, bossy, impatient, but that almost comes with the territory - being the eldest and having a lot of responsibility at a young age. Because my mother worked and was divorced, I basically ran the household as a kid. At 12, I was cooking dinner for five, making sure everybody had a bath, paying the bills. I did a lot of stuff a grown woman does. It added to me being methodical; I know how to put one foot in front of the other to make things happen."

When McMillan was born in 1951 in Port Huron, a small town in northern Michigan, her mother, who had five children by the age of 23, cleaned houses, tended bars and worked for Ford motors. "She hated welfare. She never used the word 'poor', because we never went hungry. She didn't have any money, but we ate every meal, and if our clothes weren't brand-new, you'd never know it. My mother had her ways, but I wouldn't have traded her. As much of a bitch as she could be, I loved her." She sees an inheritance in her manner: "No frills, direct and matter-of-fact; she didn't bite her tongue. I love that about her. My baby sister and me have a reputation for not beating about the bush."

Her parents divorced when she was 13, and her father, Edward, a labourer, died three years later.

"I didn't know him that well, but he was a good person," she says, adding that she made Cecil, Viola's husband in the novel, "the father I wanted to have: tolerant, loving, honest, a hard worker, who respects women and only wants to do what's right; he has a conscience".

Her mother married five times - twice to the same man. At 14, Terry threw one of her stepfathers across the room for threatening her mother with a knife: "It was no big deal, everybody used to fight where I grew up. He was harmless, except when he'd had too much to drink." Her mother thought Elizabeth Taylor had nothing on her. "She married half the guys just so they could help her with the rent. You didn't shack up in those days," says McMillan, who discerned other reasons as she grew older: "It was her way of commanding respect: 'If you respect me, you'll marry me, with my five children.' She got rid of them when they didn't work out. I'm pretty good at that, too."

Another point in common is that one of her mother's husbands was more than 15 years younger than she was. "My mother broke the rules back then, which I admire," says McMillan. "She said, 'People will always judge you, so you might as well do your own thing. But have respect for other people - and God don't like ugly.' It was her version of preaching." All the siblings but Rosalyn, who married young, and went to college. If the children used slang, "my mother'd pop us upside the head". She used to say, McMillan adds raising her voice, " 'Every last person in this house is going to college and make something of yourselves. You're not having babies before you do - see what happened to me.' It's not the kind of thing little girls - especially little black girls - were being told in the 60s."

McMillan first began to read at 16, during a job shelving books at the local library. From a background oblivious to Black Power (Mildred, the mother of five in Mama, sports a platinum wig at the height of the 60s), she discovered Malcolm X and other African-American authors at college in Los Angeles in the 70s. "My world opened up." She began by writing poetry ("It was my way of trying to fix what I thought was broken"). She took a fiction writing class at Berkeley, where she majored in journalism. "I loved the power of words, and what they can do if you use them right." Seeing herself through Columbia film school while working part-time as a legal secretary ("I'd often catch the lawyers' mistakes"), she joined the Harlem Writers' Guild in New York.

But for a time she was stymied by cocaine ("I had friends in the music industry") and alcohol. "I drank for about four years," she says. "There's alcoholism in my family - my Dad and everybody on his side." When she was 30, "My son's father said, 'Do you just want to be the kind of writer who gets drunk and never writes anything?' I'll always thank him for that. When I looked in the mirror, I saw my mother's face." She tried Alcoholics Anonymous ("The first time, it was depressing as hell. Me and another guy left to get a drink") and finally quit on February 22, 1982. "I haven't had a drop since - never missed it."

She had Solomon aged 32, and soon afterwards left his father, Leonard Welch (who later filed an unsuccessful $4.75m defamation suit against her and Penguin USA, alleging that Franklin, Zora's lover in Disappearing Acts, was modelled maliciously on him). She wrote Mama, set in 60s and 70s Michigan and Los Angeles, while a single mother, edited it on the New York subway, and fired off 3,000 letters to bookshops and the media in a self-driven publicity campaign. Disappearing Acts, which did draw on her relationship with Welch in the 80s, was written when she was visiting professor of creative writing at the university of Wyoming. Waiting To Exhale, set in Phoenix, followed while she was associate professor of English at the University of Arizona.

In Looking For Mr Right, an article for Essence magazine in 1990, McMillan wrote of loving men who did not "take life as seriously as I did". She lamented that many seemed threatened by intelligent women of independent means, and required passive subservience of their lovers. "It wasn't just me; a lot of women I knew were in the same boat," she says. "We'd gone to college - some of us had master's degrees - and for the most part were not unattractive. It seemed unfair that we had to struggle to get a date. We wondered, 'Why are we always going out with losers, or with men who have assimilated so much they don't even know who they are any more?' "

The film, in particular, of Waiting To Exhale, found critics: the writer bell hooks said it was "so simplistic and denigrating to black women that we should be outraged to be told that it is 'for us'". McMillan objects: "We were heterosexual women not wanting to apologise for wanting to have a mate, a guy, in our lives. Everyone wants companionship and to feel loved; it's a basic human need, and there's no shame in being vulnerable. bell hooks said, 'Don't those women think about anything else?' Yes, sure. But the focus of my story was their love lives." She adds: "Being a feminist doesn't mean you renounce men or don't need to be loved - give me a break." As for the criticism of showing black men in a bad light, she responds, "It was women making bad choices; we're the ones who picked these creeps. It was about us taking more responsibility."

McMillan women seek love on their own terms. "My attitude," she says, "is something is not better than nothing." Waiting To Exhale brought fame, but she says: "No one was more surprised than me; I didn't think it would last but 15 minutes." She is scornful of her imitators ("All these books with four girlfriends. Can't it be three, or eight?"), whose motives she questions: "A whole lot of folks deciding to write books to get rich and famous." She adds, "I got thrust into a role I didn't ask for. They're always looking for the 'next Terry McMillan'. And this is the bit I resent: that because my books are so popular, critics put unfair labels on them.

They call it 'popular fiction' and don't want to take it seriously. But white people, especially white men, have defined what literature is, and I reject that definition. Look at Virginia Woolf or the Brontės. They wrote about their era in their own language, but because they're pristine white women, their literature is made out to be more valid than mine. Well, I don't buy it. I've chronicled the black experience, and people who read it see it as accurate and valid. That's good enough for me."

She saw How Stella Got Her Groove Back as being about liberation. "It's what my mother was about: choosing your own course, doing it your way. The double standard upset me. I thought, why should I feel so bad that I like a younger man - men have been doing this for centuries. For me, that's a feminist position." She insists older woman meets younger man was only part of the story. "He was a catalyst, and the movie glamorised that part. In the book it was Stella trying to give herself permission to do what she wanted to do. So many women suffer from guilt, and fear being ostracised because of what others might think. I wanted her to come to the realisation that she wasn't happy. It happened at the same time as a younger man. It was about shedding your own skin."

Of her own marriage, McMillan says: "I think of it as an adventure, not a risk, but it doesn't mean it's not scary. You have to put yourself out there, or forget it - I'd still be an alcoholic. When you settle for things, that's when life gets boring." She once said she was preparing Plummer "for some other woman" - "the chances of our sitting on the back porch in a rocking chair are slim to zero. But if it doesn't happen, hopefully he'll have learned a lot from being with an independent and secure woman. Somebody might get herself a grown-up - if he pays attention. I'm not looking at myself as a teacher - we're both growing. But I'm an honest person and I'm not playing games."

Sensitive to putdowns that she writes with one eye on Hollywood, she has so far refused to sell the film rights to A Day Late And A Dollar Short. "It cheapens it, as if, when the book comes out, people are asking, 'When do we get the knock-off?' " She loathed "writing by committee" on Stella, whose friend was played by Goldberg in the film. "You write a book, one character is dead. You sell the movie rights, and they want to know, can you bring her back to life? We think we've got the Whoopster ..." Yet McMillan is toying with the idea of a TV serial of the new novel, "with a focus on different people's lives, their triumphs and joys - not a sitcom, but a soap opera without the melodrama".

In her anthology Breaking Ice (1990), with which she used her name to boost some 60 other African-American writers, McMillan hailed a "new black aesthetic" where "race is not the only source of conflict", and which reflects "how our lives have changed" since the protest writing of the 60s. Some have seen her as a worrying precedent, that, if you want to make it, don't write about race. But her characters have a keen though casual awareness of that pathology. "I do write about race," she insists. "But it's more subtle: some of the things that happen to my characters may or may not happen because of their colour."

She has said her politics are emotional. "It's because we're all products of our parents," she explains. "Unless you're smart enough to see how they screwed you up - and that takes some work - that has a lot to do with what you become, and how we treat each other." It is a touch ironic that McMillan should be admonished for flaunting brand-names when the most consistent values espoused in her writing are education and good parenting. She shares Oprah Winfrey's emphasis on self-improvement and self-reliance, with her own life a prime model to her fans. "Literature to me is about hope; it's life-affirming," she says. "I don't want to read a book and get depressed. I can do that by myself. I give all my characters flaws and problems that they're trying to overcome; that's what makes them real. But even though they may be victims, they don't know it; they're still rebelling and resisting bullshit that's trying to pin them down. They're not going to roll over and say, 'This is my lot'. Passive people bore me to death. People I write about, even if they don't do it right, the bottom line is, they're trying"