When Jennifer Weiner attends the premiere of "In Her Shoes" — based on her 2002 chick-lit best seller — she'll wear a brand-new hairdo.
This past summer, the 35-year-old and her younger sister, Molly, an actress, both had identical geometric bobs. But since sis is one of her dates for the premiere, Weiner grew her brown hair shoulder-length, added blond highlights and loose waves she says are very "in" for fall.
"I decided we couldn't both have the same hair on the red carpet," she adds with a laugh.
The way sisters compete and relate is the subject of Weiner's novel and the movie, directed by Curtis Hanson ("8 Mile") and adapted into a screenplay by Susannah Grant ("Erin Brockovich"). Like the book, the droll but heartfelt film revolves around Jewish siblings who have nothing in common except size 8 1/2 feet and a wicked stepmother. The fictional Maggie (Cameron Diaz), a size 0 babe, is an irresponsible party girl with dyslexia. Rose (Toni Collette), a frumpy size 14, is a successful attorney with low self-esteem about her looks and her love life.
Rose collects shoes to make herself feel better; Maggie covets and pilfers the boots and high heels.
It is only when the sisters reconnect with their long-lost grandmother (Shirley Mac Laine) that they learn to make peace with each other - and the footwear issue.
The shoes become a metaphor for all the ways the sisters are jealous of each other - "for wanting to inhabit someone else's skin and get what they get out of life," Weiner says.
As she wrote "In Her Shoes," she wanted to work through an obvious, but puzzling, conundrum: How can people who grew up in the same house wind up radically different individuals?
The blond, blue-eyed Cameron Diaz looks less like either Weiner sister and more like the gorgeous WASPs both siblings grew up with in Simsbury, Conn.
The dark-haired Weiner "felt like an outsider in so many ways," she told the Journal in 2002. She says she was "funny-looking," brace-faced and plump. On her youth trip to Israel, where there were four other Jennifers, she was labeled "the fat one."
Weiner spent the next decade dieting and seeing nutritionists - until she had an epiphany in the late 1990s. "It had been 10 solid years of trying to get somewhere my body didn't want to go," she says. "And I really just got to the point where I thought, 'How much more nonsense am I going to put myself through, and how much time am I going to waste?' ... And I said, 'I am through with this, and I'm going to work with what I have and try to be happy and take some of this energy and put it someplace else.'"
The energy went into writing her semiautobiographical debut novel, "Good in Bed," whose troubled, zaftig heroine winds up living happily ever after without shedding a pound. That's more or less what happened to Weiner, who is now married to a menschy attorney, with a 2-year-old daughter and a stellar writing career to boot.
Her wickedly witty but flawed heroines have made her the biggest chick-lit success story since Helen Fielding burst through with "Bridget Jones's Diary," according to Entertainment Weekly. The Jerusalem Post called Weiner the Jewish girl's answer to Fielding.
Weiner says she enjoys creating Jewish, plus-sized heroines, partly because she is writing what she knows, and partly because such characters are often invisible in the popular culture. Heavy women, especially, are ignored or played for laughs.
Considering Hollywood's weight phobia, Weiner felt victorious when actress Toni Collette ("The Sixth Sense") agreed to gain 25 pounds for the film. Collette has admitted she was reluctant to put on the weight.
"But I love my character and I think the extra pounds are pertinent to the way Rose sees herself," she said at a press conference. "She overlooks herself, and I think most people walking past her would probably do the same. But as an audience member, you get to know her and you see her getting to know herself ... Her name is Rose and you really watch her blossom."
The movie also features amusing, if occasionally cliched, Jewish characters based on residents of the Florida retirement community where Weiner's grandmother lives. There is a joyous Jewish wedding and a grotesquely caricatured Jewish American Princess, the sisters' wicked stepmother.
Weiner - who finds the character "recognizable" - loves the scene in which the "stepmonster" gets her just desserts. (She discovers that her biological daughter has joined Jews for Jesus.)
If the fictional sisters enjoy their Cinderella-like happy ending, so does Weiner. Her books have sold millions of copies worldwide; Hollywood is snatching up the movie rights, and her latest novel, "Goodnight Nobody" (Atria Books) just hit bookshelves.
And then there's the "Shoes" premiere, where the author will sashay down the red carpet not in glass slippers, but in strappy Nine West silver stilettos.
Perhaps she's hoping her sister will wear something else.
The film opened Oct. 7 in theaters nationwide.