I've just started doing before/after care as well. I do charge for stat holidays, and for PA days and March Break I charge the full day fee. For only after school I charge $12/day/child. And yes, I changed my contract for clients who are doing before/after care. As for homework, I ask the parents if they would like their children to work on it here or wait until they get home. I let them know I am willing to help the kids with homework, but I make sure they know it's not a guarantee--I am busy with other kids too!