For Vanessa Williams, joining the cast of Desperate Housewives (ABC, Sundays, 9 p.m.) as well-heeled diva Renee was like being the new student at school -- except the cool kids have been happy to sit with her in the cafeteria. "I've shot seven episodes so far, and the cast have all told me I'm going to be great for the show," the unattached star -- and mother of four -- tells Us. "I got three Emmy nominations from Ugly Betty. So it's nice to be a commodity that people want on their team." Williams, 47, talks to

Us: Renee is so arch, it seems like she could be Wilhelmina Slater's long-lost twin sister.

VW: Wilhelmina wreaked havoc and created fear in the hearts of nearly everyone that she dealt with and had some diabolical schemes. Renee is a lightweight compared to that! She's more passive aggressive. But a narcissist.

Us: You're going to have a fling with Brian Austin Green's character soon. How steamy is it?

VW: Unfortunately, I'm not the one who gets the racy bedroom scene. But her fling does set up some friction with Bree.

Us: Between Ugly Betty and your recent run on Broadway, have you had time to catch up on all things Wisteria?

VW: The first season I was a big fan. Then I started shooting a show in Miami called South Beach. From there it's been series after series. After I signed up, I did my homework! But I do have a lot on DVR. I watch Real Housewives of New Jersey and Saturday Night Live religiously every week. And then pretty much every design and bridal TV show.

Us: What have you learned from being in the business for 25-plus years?

VW: Sometimes you do what you love and feed your soul and sometimes you do what you have to do. I've raised four kids as a single mother. I'm raising them and paying for their college and I got to make money. That's the bottom line.

Us: Staying gorgeous helps too. What's your favorite workout or beauty routine?

VW: I dance when I can. Salsa is a phenomenal way to stay fit, have a great time with your friends and listen to great music.

Us: Speaking of which, your ex-husband Rick Fox is on Dancing with the Stars this season. Thoughts?

VW: I was surprised he signed on. But when I heard that he got Cheryl as a partner...she's a phenomenal choreographer and coach and works really well with the athletes. Those two will get a lot of mileage.

Us: Would you do it if you were asked?

VW: I wouldn't want to at this point. I played a dance instructor in a movie already. [1998's Dance With Me]. My work speaks for itself!

By Mara Reinstein for