I have dogs also, have never really had too much issue (lasted long) with a child being afraid, that IS always one of my questions apon meeting the family, I ask of allergies or fear of animals (we have alot of animals). if she is ok with dogs everywhere else I would wonder if its the size of him that bothers her, or maybe she was knocked down by a bigger dog, and she is associating that with your dog? I always have the kids who are a little leary of my dogs, come to them (with me) pet them and give them snacks, maybe show the child some tricks, but the most important thing is they learn to become comfortable with ALL members of our household including that animals, Def give her time to adjust, but worst case, she doesnt? its not worth the stress on you everyone else and mostly the dog. Even the smartest animal is still an animal, if a child makes them uncomfortable they could make a mistake (growl/bite?) you def dont want that. They MUST become friends! Good Luck