BOOKS Actress focuses on universal experience in debut novel Molly Ringwald, who became a teen idol for her roles in "Sixteen Candles," "Pretty in Pink" and "The Breakfast Club," is now 44 and living in Los Angeles with her husband, Panio Gianopoulos, and their three young children, Mathilda, Adele and Roman. Why betrayal as the subject for your novel? The book starts with a marital betrayal, but the stories are really about all kinds of betrayal. All along, I had in mind a different ending, something more cinematic, like Olivia walking into school. [...] once I have Marina in that shop and Marina says (to the saleslady) that the dress "is for my daughter," that was it. Didn't Bret Easton Ellis read this novel and comment on that particular scene, saying in his mind that Marina should have said, "It's for my son"? Have you thought about what you would do if your son announced he was a she? [...] I don't think you ever really know until you're in that situation. Torture or fun or somewhere in between? Some days it comes naturally, and that feels glorious, and other days it feels like you are trudging through cement that's drying. [...] I'm a working actor and a mother, and some days it's not possible to get there. Was it unsettling for him to read this work, given the marital mess? How do you feel toward Phillip, whose betrayal is ugly and chronic? [...] it has helped with character development. Were you always meant to be a writer and took a detour as an actor, or are the worlds symbiotic? If this debut novel becomes a film, who will you play? If the book became a film, which I'm hoping it does, I would want to play Marina. Molly Ringwald will be interviewed onstage in a fundraiser for Litquake by co-founder Jane Ganahl at 8 p.m. Thursday at the Verdi Club, 2424 Mariposa St., S.F. litquake.org.