''They used to say 35 was a woman's sexual prime. Listen, 40 is when it really starts to get good. Oh, honey!'' Cybill Shepherd, 44, sitting cross-legged on a couch on the set of her new CBS sitcom, spears a limp stalk of broccoli from a plastic takeout container on her lap. She sneaks a look around the fake living room to see if the crew can hear, then lowers her voicebut not by much. ''For me, it was about getting over the fear of saying what excites me. It was about finding a man you can feel safe with and tell what you like, who will tell you what he likes.'' Shepherd takes a swig from her mug of chamomile tea. ''It's only taken me, uh, like 20 years to figure all this out. Twenty years to figure out how to be myself.''
Talk about timing. Her new series, titled simply Cybill, is loosely modeled on Shepherd's real life, so now she has to figure out how to be herself on screen as well. In the show Shepherd plays an actress who is also a single mother to two daughters by two different fathers. She says it's really the story of what her life would have been like had she not hit it big with Moonlighting (1985-89) a journeywoman actress with a bunch of kids by different men. (Off screen, the twice-divorced Shepherd has a 15-year-old daughter, Clementine, by her first husband, former auto parts dealer David Ford, and 7-year-old twins, Ariel and Zachariah, by her second husband, chiropractor Bruce Oppenheim.) But unlike the situation with her last series, the strife-ridden Moonlighting (in which Shepherd says she was the ''scapegoat'' in battles with costar Bruce Willis), she is a coexecutive producer of Cybill. More important, she claims, is the so-far idyllic relationship she shares with coexecutive producer Jay Daniel (late of Moonlighting) and series creator and coexecutive producer Chuck Lorre. They are two men with whom Shepherd evidently feels safe enough to say what she likesand what she doesn't like. ''I feel like I finally have a voice,'' she says, ''and people to listen to me.''
It's still dark when the silver tour bus that serves as her on-location dressing room glides through the deserted streets of Studio City and past the CBS gates to Stage 15, right near the intersection of Gunsmoke Avenue and Newhart Street. With the show's debut less than a month away, Shepherd will work a 15-hour day today, mostly rehearsals with a couple of taped scenes that are too complex to do in front of a studio audience. It's a grind, but Shepherd, the Memphis-born model-turned-actress of a certain age, is facing her own crossroads in Hollywood. Since her early triumph in Peter Bogdanovich's The Last Picture Show (1971) and her nasty fall from grace after movies like Daisy Miller and At Long Last Love, Shepherd has made a career out of comebacks. But she knows that her luck could run out. ''I'm at the age when the double standard really kicks in,'' she says. ''But times are changing. I wanted to deal honestly with a woman character who's in her prime sexually and in every other way.''