It really sounds like she just needs more socialization both to humans and other dogs. It doesn't sound like she is mean, but just frightened of people she doesn't know and other dogs.
The fact that she wags her tail and rolls over on her back with people she knows means she is a friendly dog to people she knows. In fact, rolling over like that is a sign of submissiveness, not aggression.
I'd just work on exposing her to more and more positive experiences with nice people and nice dogs to build up her confidence. |