IF SOAP OPERA WERE A SPORT, SARAH Michelle Gellar would be Rookie of the Year, a league leader in schemes hatched and taboos trampled. In her 14 months as Kendall Hart, Erica Kane's she-devil of a daughter on ABC's All My Children, Gellar has tried to seduce her stepfather (Michael Nader), left her 8-year-old half sister in the care of a man who once raped her mother (Susan Lucci) and brought buzz back to the 24-year-old show. That's a lot of responsibility for Gellar, who, though she looks 24 (Kendall's age), is just 17. After a day's labor, "it takes me an hour to unwind," says Sarah. "But it's a great way to get out all my frustrations."

That's not the only benefit. Gellar recently won a daytime Emmy nomination for Outstanding Younger Actress. Lucci, meanwhile, a 13-time Emmy bridesmaid, went conspicuously unnominated this year, and there were rumors that she resented her costar's success. "Susan's a pro," counters Gellar. "She congratulated me." Lucci, who will be host of the Emmys on May 25, confirms she bears her colleague no ill will. "I think Sarah's terrific," she says. "I hope she wins." Still, La Lucci can be intimidating. Gellar was "shaking" her first day at work until "Susan put her arm around me and said, 'Don't worry, nobody bites.' "

Nobody had better. Gellar, a native New Yorker, learned karate when she was 10. But acting was always her biggest kick; the vet of 100-plus commercials even played the young Jacqueline Bouvier in the 1991 miniseries A Woman Named Jackie. An only child, she lives in Manhattan with her mother, Rosellen, a nursery-school teacher who divorced Sarah's father 10 years ago. These days there is scant lime for dating, but Sarah's preference is for actors. Reasons she: "A guy in the business knows what it's like when you've had a bad hair day."