I may be missing something, but I don't know that I would interpret either situation as a "social skills" issue as much as learning how to deal with others who don't either share one's enthusiasm (first situation) or who are just plain rude (second situation) without getting too upset. I think she handled situation 2 perfectly. If those girls were ignoring both the coach's directions and her being there, absolutely no point in sticking around. The girls were the problem, not your DD.
The teeth and growling thing is a bit more unusual, what does she say when asked about it?
I agree, and I'm not sure what she could have done differently about the ball throwing. She asked them to throw to her and they didn't so I'm not sure what else she could have done? Maybe she could have told the coach they wouldn't play with her, since it seems like bullying behavior, and let the coach deal with it?
She is still pretty young at age 10 and I think a lot of girls that age are still pretty awkward socially. If she wasn't making friends, was by herself a lot of the time, or was being bullied regularly that would be different.
