For years Chastity Bono lived in her parents' shadow. She tells EMMA COOK how she forged her own identity
It was never going to be easy being Cher's daughter. The ego, the personality - that dress sense. The prospect of parents' evening, for a start, must have been truly terrifying. Would Cher wear her translucent cobweb number or - horror - a sequin thong to meet the new geography teacher? Then there'd be the really embarrassing stuff like meeting her youthful boyfriends - which one could be your potential stepfather?

It's difficult to imagine how any daughter could compete or even feel an equal to a woman who has sung in concert astride a mock nuclear missile, wearing little more than a black leather handkerchief. The answer for Chastity, Cher's 30-year-old daughter, was not to try. "I've never compared myself with Cher physically. I'd drive myself crazy if I did that. There's no way I could compete on any level," says Chastity. "There's not a lot of people who have the personality and live the sort of life my mother has, and I'm certainly not one of them."

Instead she's forged her own identity - which includes having told the world that she's a lesbian. On the back cover of her new book, Family Outing - part-autobiography, part self-help book for those considering coming out - there is a telling photograph. Cher, jet-black hair cascading to the waist, wears a mad, floral Seventies kaftan and stares proudly at her daughter. Chastity, pretty with white-blonde hair, about four years old, somehow looks distant. Wearing an identical floral dress, her small back is turned to her mother and she stares off into the middle distance.

No wonder young Chastity craved jeans and DMs. "I have a photo of us together in matching black catsuits. She's smiling at me, and I'm clapping my hands. But I have no memory of that moment," she says. Similar photographs, also in the book, look a little hollow now. "I think I stopped wearing dresses and skirts a lot younger than my mother recalls," says Chastity. "It's as if I began to change and have definite tastes, but my mother clung to this image of me in a frilly dress."

After years of feeling "different", not just to her mother but other girls, Chastity came out as a lesbian, aged 18. Her mother was the first person in her family to find out - in rather a shocking way even by Cher's flamboyant standards.

She came home one evening and stumbled across Chastity and her girlfriend on the sofa. Cher was furious but decided not to confront her daughter. Instead she swept off and ignored the incident. When Chastity told her mother she was a lesbian soon after, Cher couldn't accept it. At one point she told her, "This will only push us farther apart. I want you to leave the apartment right now."

Still, Chastity is generous about her mother's expectations. "I think parents look at their children as extensions of themselves. Parents want children to fulfil their own dreams. I think my mother's hopes were fairly normal; she wanted me to have kids, get married and be heterosexual."

Instead, Chastity rejected her mother's femininity - "I don't know if it was a form of rebellion or if I was trying to find a new identity," she says. Once Cher took her daughter to a shoe shop and bought 20 pairs of the same shoe in different colours. "I'd say, `Don't you think that's a bit excessive', and she'd just laugh. And when I was 13, Mom said she wanted a mohawk. I was like, `Please, please don't do that.'"

While Cher has gone to every extreme to look vampy, young and feminine, Chastity has taken every precaution to look anything but. For every pound Cher loses, her daughter seems to put one on - and to don another pair of scruffy jeans for good measure. It's an understatement to say Chastity is the antithesis of Cher; in terms of appearance, it would be hard to spot the family resemblance.

Although Cher had gay friends, she found it hard to accept her daughter's appearance and behaviour. Chastity is understanding about this: "It was upsetting for her. It was a typical parental way of coping. She felt disappointed, embarrassed and angry. She thought it was a reflection of her parenting skill, like, `What did I do wrong?'"

Soon after her daughter's confession, Cher offered to go into therapy with Chastity to try to salvage their relationship. "Deep down, my mom had long suspected I was gay, and felt terribly burdened by my secret," says Chastity. From a very early age, she says, she knew she wasn't the same as other girls - and not just because of the dresses her mother encouraged her to wear. Cher also suspected Chastity's aversion to frilly petticoats was more than a fashion statement. Chastity says, "When I was 13 I finally found a name for exactly how I was different." She was watching a film with a lesbian storyline and everything fell into place.

Her father, Sonny Bono, was far more sympathetic. "He was so understanding," she says. "It was easier for him, perhaps because I was closer to him at the time. I just related to a male figure far more." They divorced when Chastity was four ("I have a blurred memory of the emotional chaos") and she spent her childhood being shuttled from one parent to another.

She remembers playing football with her father in the backyard and how he would encourage her tomboy sensibilities: "He didn't reject that side of me - he wasn't afraid of it." Yet if Cher displayed a conservative reaction that eventually gave way to acceptance, Sonny seemed to be the opposite. In an awful irony, he went on to become a Republican congressman, and backed congressional moves to ban homosexual marriage. "It damaged our relationship greatly and we ended up on opposite sides of some very important issues," says Chastity, who was barely on speaking terms with her father when he died in a skiing accident more than a year ago.

Chastity, who came out publicly four years ago and now campaigns for Gay and Lesbian Alliance Against Discrimination (GLAAD), hopes the way she dealt with her parents' reactions will help others in her situation. She is currently working on a documentary treatment of her book, which, in places, falls into the Oprah Winfrey self-help mould. Still, though, it drives home just how traumatic coming out can be, regardless of your celebrity legacy. "It's no different. Parents still think, `What will the neighbours or the country club or whoever say?' It was just the same with Mom." It is more traumatic, though, she says, coming out in America. "In Britain you don't have that strong religious right element. They've really latched on to gay issues and go out of their way to propagate anti- gay feeling."

Meanwhile Cher, who has completely come to terms with Chastity's sexuality, is said to be proud of her daughter's book. "Initially, she was paranoid that she'd come across as the bad guy," says Chastity. "But I see her as the typical parent who overcame her fears. If anything she comes across as a real hero."