Ron first off, I sincerely hope your daughter is o.k. Now for the "pitbull" b.s. I have American bull terriors or "pitbulls". rescued one from a shelter 12 years ago and she will bite without warning any grey haired man....We were told she was beaten by an older guy, but absolutely no one else and there have been plenty of chances around kids,women,men you name it. We tell every one we know may come around " no grey haired men" and there are no problems
When my daughters were 3 and 4 we heard them laughing at 2 a.m. We got up and follow the voices to the laundry room where hey had gotten out of bed and moved the baby gate where the dog was in labor. the dog was having pups. one of the girls was sitting on the dogs side, the other was holding the newborns. nothing, no reaction from the dog at all.
I have a newer one too and they are both really sweet dogs. I have however had several mixed breeds that have been put down for biting over my lifetime.
Bottom line, raise any dog right and it's a good dog. Like Ron said dogs are territorial, ALL of them.
But for what it's worth, I would have the dog put down too if it was an actual bite, instead of an excited, untrained dog grabbing a cookie.