Charlotte's Web

Julia turned 39 this year, but she says she's not nervous about approaching 40. So what does she know now that she didn't know at age 25? "I guess I appreciate life more. I can appreciate being fulfilled and I don't feel like I have to be constantly striving," Julia says.

Now that she's a mother, Julia also says she can better appreciate her own mom, Betty. "I try to call her with more regularity because I think, 'God, what if Hazel didn't call me for two weeks?'" she says. "I'm able to see her mothering now from a different vantage point."

Julia also says being a mom has made her think more critically about global issues. She was recently featured on the cover of Vanity Fair magazine as part of the "Green Team," along with George Clooney, Robert F. Kennedy Jr. and Al Gore, to promote environmental awareness. "It's motherhood really urging my consciousness along into different places," she says. "What is the world going to be like for all of our children?"

Julia drives a hybrid car and even makes sure to recycle plastic grocery bags. "Reduce, reuse, recycle," Julia says. "Just like Jack Johnson sings in Curious George."

Julia is also involved in a program called School Bus America to try to get school buses across the country to switch from diesel fuel to biodiesel. "Our kids are inside those buses where it's so much more toxic and deadly," she says. "And it's so easy. All these buses can be changed over to biodiesel and vegetable oil."