According to The Hollywood Reporter, America Ferrera did not want to sign on to do the sequel of The Sisterhood of the Traveling Pants. She had no choice because she signed a sequel option when she did the first one. That movie came out before she did Ugly Betty and her co-stars were on successful shows and got higher billings than her. Now that she has won awards for Ugly Betty she had other options she was looking into during her summer break and now she has to turn them down for The Sisterhood of the Traveling Pants 2.
I can't say I blame her, the first movie was good but it was good a one-time movie. A second time around I think will be cheesey. Not every movie needs to be made into a sequel and this one is no exception in my mind, I mean wouldn't it be smarter to do it with a new set of girls trying out the pants?