Hilary Duff admits that she is feeling "overprotective" of her newborn baby.

The 24-year-old actress and her husband of 18 months Mike Comrie welcomed son Luca Cruz Comrie into the world this week.

Although Hilary is enjoying motherhood thus far, the power of her instinctual maternal nature continues to shock.

She wouldn't consider allowing her infamous co-star Charlie Sheen, whom she shares the screen with in upcoming comedy feature She Wants Me, to watch Luca.

"Of course, I would never let him babysit my kid. I think everyone is really cautious about who they leave their kid with," Hilary told OK! magazine.

"I think it's hard when you feel so connected to something and protective over it. You want only the best for it, and I think you become a little extremely overprotective."

Hilary can't wait to share with her little one some of her favourite childhood stories.

"I have boxes of some of my old books from when I was a kid," Hilary gushed. "There's a book that I love so much called If You Give A Mouse A Cookie. It's a really cute book. I grew up reading it. My mom read it to us, and it's one that I really loved and kept going back to over and over again. And all the Shel Silverstein books I really loved, like Where The Sidewalk Ends and The Giving Tree."