I really didn't think they would, either. I wasn't expecting a big deal over it, I didn't plan a party or anything, and at most I was expecting a card with $50 inside. Money's always tight in my house, but they said they thought about it and said, "This'll be the only 16th birthday she's going to get, and what better present to get her?"
Plus I think they figured it was cheaper than a car or something.