Hilary Duff's been one busy mama since welcoming son Luca Cruz to the world 5 weeks ago. The new mama's been sharing family photos with her fans, trying to return to her prepregnancy workouts, and getting back into her daily routine. Now Hilary's about to become even busier as she joins Johnson's Baby and Save the Children for the launch of Johnson's Baby CARES, a new initiative to support the basic needs of families during natural disasters. The actress and recording star took some time to answer our questions about the campaign, as well as her initial thoughts on new motherhood.

LilSugar: What's been the most surprising thing about motherhood so far?
Hilary Duff: How much I fell in love with Luca from the moment I saw him; it's so cool to see your child changing every day.

LilSugar: And the most challenging?
HD: Getting Luca on a schedule that works for both of us, it was tough at first, but he is getting better every day.

LilSugar: Who does lil Luca look like?
HD: A lot like me when I was a baby, but he has his daddy's nose!

LilSugar: How did you come up with Luca's name?
HD: Mike [Comrie, Hilary's husband of a year and a half] and I were just bouncing names off each other and Luca just stuck. We both knew when we heard it — it was unique, but not crazy.

LilSugar: Have you and Mike gone out on a postbaby date yet?
HD: Yes, we've had a few dates since Luca's arrival. At first it was nerve-racking, but the second date went a lot better. It's important for Mom and Dad to have time together.

Keep reading for Hilary's thoughts on postpartum exercise and her decision to partner with Johnson's and Save the Children.