been there...i had problems with my daughter's grade school. she was harassed endlessly. she went to a catholic grade school school and to this day (she's 19) she won't set foot inside a church. schools are ill equipped to deal with social issues like bullying etc.
i would seriously consider transferring schools, if at all possible. if not, get in their face and stay there. it will be hard for your daughter - you may want to get her some therapy. sounds extreme, but trust me. yes, she needs to learn to deal with idiots, but she also has the right to be herself without recourse.
If it's any consulation, my daughter is a freshman in college and is on the dean's list. she's made good friends, but at times has trust issues.
As for me, I'm no longer Catholic for those and other reasons. And I'm very content.
Best wishes, hun.