Celebrity Moms' Instagram Pictures Week of Sept. 2, 2012

It's back-to-school season in Hollywood! With Labor Day behind us, it's time to hit the books in Tinseltown and throughout much of the country. All we had to do was turn to Instagram to see some of our favorite celebs say goodbye to Summer and hello to the new school year. Check out celebs' best social media photos of the week, from first-day-of-school photos to handmade birthday cards from toddlers to new additions to the family!