I don't blame the dog or the child, I blame the adults. This dog was clearly giving signs of having enough and the adults did not pay attention and allowed the child to torment the dog and the dog did what it felt it had to do. Unfortunately now the dog is going to be labled aggressive all because the adults did not properly supervise the child and dog together. I am sorry but 13 staples in this child's head was not a little nip and it makes me really angry that it was allowed to happen.
When my dogs are at work in the assisted living, they have their place they can go to get away from people, it happens to be on a dog bed under my desk, when they are under the desk, it is offlimits to everyone but me. If my dog goes under the desk they are telling me they have had enough visiting and they need a time out. Your dog did the same thing and her wishes should have been honored and the adults should have kept the child away from her. I also do not allow children at the assisted living to chase or follow my dogs, if my dog comes to them and wants to be pet by them, that is fine but I will not allow children to torment them, that is not why they are there.
You as the dog's owner and the parents of the child should have been in control of the sitsuation and you were not, sorry to be so blunt and I am sure I will offend, but this was your fault not the dog, not the child.