Actress Amanda Peet, who welcomed her first child, daughter Frances Pen (named for her mom, Penny) in February, is feeling the rigors of new parenthood.

But she says it's worth it.

"I'm very busy with my baby - I have to get back to my projectile-vomiting baby," Peet, 35, told People at Wednesday's Oscar de la Renta boutique opening in West Hollywood benefiting the Women's Cancer Research Fund.

"In the beginning, it's very, very hard because you're so sleep-deprived. But she just started smiling three days ago, so I'm on cloud nine right now."

THG NOTE: You know who's been smiling a lot lately? Britney Spears. We think she's on massive amounts of anti-depressants. Moving on.

And Amanda Peet and screenwriter husband David Benioff are already thinking about adding to their family. "I think we want more [kids]," she said. "He wants three, but I'm old, I'm an old lady. Two is enough!"

Asked who has been giving her child-rearing advice, Peet said:

"My mom has been fantastic."

David Benioff also has been doing his part.

"Changing diapers. He's actually doing the night-feeding," Peet said. "He's letting me sleep right now. The hardest part is being so monumentally sleep-deprived."

Benioff and Peet dated for four years before tying the knot in September at Peet's prep school alma mater, Friends Seminary, in New York City.

Peet, like Salma Hayek, Keri Russell, Tobey Maguire's surprisingly average-looking fiance, Jennifer Meyer, and a host of other celebrities, got knocked up before tying the knot. It's the in thing to do.