Wow...lot's of good, interesting and funny replies and advice. Also, not a troll thread, this is real
This is very tough for a dad, and dads with kids know this. She's not the confrontational type, although this is one situation in which I wish she would at least say something to the girl or just blow up screaming in her face. Right now school is out so there will be a break and we'll see what we can do this summer as a family and maybe finding her another hobby that she may enjoy. But my fear is that this shit will just start where it left off once school starts up again.
As for friends, she has friends but these "friends" won't stick up for her when this other girl talks. That's the other part that really gets my daughter upset. So it's as if she doesn't have friends or any support.
As for the Prozac, I really don't like this idea, I think the main cause of her stress is the social aspect in school. If she were happy socially then I feel like everything will be fine. I can understand a conflict here and there but this jealousy shit is nuts. And yes, jealous girls look to tear eachother down, it's sick.
We have tossed the idea of boxing/mma classes around. Not that I think violence is the answer but sometimes it is. And a few combos to the face would shut the girl up. I tried to get her to join the girls wrestling team but she doesn't want to. We have at least the next 2 months to try and figure this out.
One idea the wife had was to talk to a couple of girls who have known my daughter through sports, we also know their parents so in our minds this would be an easy talk. These girls are the more well known girls and apparently were told that my daughter doesn't like them by this very girl. The thought was sort of like starving a plant of water. As this girl gets other kids riled up thinking my daughter has beef with everyone she is more empowered. If we can take that away maybe she'll shut up. This is just a thought and may have some risks. We don't know if we're going to do this or not.