Sarah Jessica Parker is jealous of moms who get to drop their kids off at school every day - because there are times she has to start work early and cannot be there for her son James Wilke.

The actress, who is now a mom of three, admits she's always caught up in the dilemma on how to be the best mom, while still working on film and fashion projects.

She tells ABC News' Katie Couric, "This philosophical disagreement about being a mother and what that means and what kind of presence you have to have in a child's life. We're all slightly envious of the other all the time.

"If I'm running to work and maybe there's parents there who aren't and they're getting to spend 20 to 30 minutes after drop-off together talking - there's a part of me that wishes I could be there. What I've learned about being a parent is how much you sort of secretly learn from everyone else and how valuable it is."

But when she's not working, the Sex And The City star loves the school run and prides herself on being very hands-on, right down to driving the ultimate mommy mobile - an unstylish but practical minivan: "Respect the van. I'm telling you it's the most wonderful car."