Call them the Motherhood of the Traveling Pants! On Tuesday, the cast of Sisterhood of the Traveling Pants reunited to celebrate the news that co-star America Ferrera is expecting her first child. Sisterhood star Amber Tamblyn tweeted alongside a pic of her and Ferrera with fellow stars Blake Lively and Alexis Bledel. The photo shows all four with their hands on Ferrera’s belly. Ferrera is the last of the four female actresses to become a mother. She and husband Ryan Piers Williams married in 2011.