Vanessa Williams's fierce turn as diabolical fashion magazine editor Wilhelmina Slater–the Ugly Betty glamazon whose stilettos are almost as sharp as her tongue–has won over TV audiences and critics alike. But there's one viewer who isn't buying the 44-year-old actress as the devious diva: a first-grade classmate of Williams's daughter Sasha, who saw a tape of Betty and sniffed, "That's Sasha's mom? Where's her ponytail?" Explains Williams: "The glam woman who wears minks and makeup all the time? That isn't me. Sasha's mom has a ponytail, wears clogs and picks up her kids from school."

In fact her Betty character is literally miles away from the actress's real life. A single mother of four–to Melanie, 19, Jillian, 17, Devin, 13 (all by her first husband, publicist Ramon Hervey, 56); and Sasha, 6 (by her second husband, NBA-star-turned-actor Rick Fox, 37)–Williams constantly commutes back and forth between the L.A. set and her house just outside New York City. "I'm home every weekend," says Williams, who split from Fox in 2004 but remains close to both her exes. "I cook for them, we go to church together–my kids are so lucky to have parents in their lives who love them and do things together," she says.

When Mom is in L.A. working, the kids are looked after by their dads or Williams's mother, Helen. But when she's at home, the actress is the CEO; equipped with a Blackberry, she coordinates who'll be picking the younger kids up from school, how they're getting to karate and basketball practice–even the logistics of getting Devin ready for his eighthgrade play. "He's going to play Birdie in Bye Bye Birdie, "says his proud mom. "I make sure he has his script."

After more than two decades in show business, Williams–who made history in 1983 by becoming the first African-American Miss America, but was later forced to relinquish the crown when a nude photo from her past resurfaced–has learned the benefits of separating business from pleasure. "Hollywood is notorious for loving you one second and then you're over with the next," says Williams, who grew up in Millwood, N.Y. "My biggest strategic move was to move out of Hollywood and live in a very normal community. None of my friends is really in the business, and I've known a lot of my friends since second, third, fourth and fifth grade. It's treating Hollywood as my job, having my home as a sanctuary and not crossing the two."

Before focusing on acting, Williams initially made her mark as a singer–racking up 11 Grammy nominations and hit songs such as "Save the Best for Last." (She's currently working on a new album with Brazilian musician Sergio Mendez.) Later she starred in the Tony-award-winning Broadway musical Kiss of the Spider Woman and in hit films such as Soul Food. Still, being on a TV show was one thing she didn't see coming. "Television was never something I aspired to do," she says. "There were certain moments in time when I watched Dynasty and Diahann Carroll came on and I thought it would be cool to be her daughter. Or when Sex and the City came on, I thought, 'God I'd love to be a part of that cast.' But I never really dreamed of being in my own TV show. It was always more about Broadway and theater."

In fact Williams, who was grieving over the sudden death of her father from a pancreatic infection in 2006, turned down the Betty producers when they first offered her the role. "I was so devastated," recalls Williams. "I said no." But ultimately she was persuaded, and she's glad she was. Says Michael Urie, who plays Wilhelmina's toadying assistant Marc: "She's having so much fun every day." And dispensing lots of advice too. On the set the veteran performer has taken on a den-mother role to Betty's cast, made up mostly of actors who have gone from worrying about how to pay the rent to how to dodge the paparazzi. "She's our fame teacher," says Urie.

Paparazzi hoping to catch Williams with a new boyfriend will just have to wait. "No, I'm not dating anyone," she says. With her schedule, who has time to meet someone? Or as she puts it, with a laugh, "I'm dating American Airlines seat 2A."