I would personally call the regional director for your school district. Through out a couple of discriminations, harrassments, and subjecting her to cruelty will get attention fast. Depending how comfortable you are with this being open and knowing that YOU can make a difference in your town for any other child-I would call the newspaper. They will write a story on it, demand a response from the school board.
My son at one point was being tested for cerebral tumor due to bleeding from his ear and frequent headaches. Most of these appointments were out of town-so he missed a lot of days. We had letters from the docs office for every missed day. The principal actually suggested to kick him out of the school so he can "start fresh" wherever he went to. The regional director nipped it in the bud and the principal-although hypocritically went along with it. The nurse and teachers worked with him to ensure that he was safe. Kept him out of running around in abundance and let him sit when tired, lay his head down when his headaches came in.
If it seems too much hassle, and you don't want to put your daughter through this, you can go to the board of education and formally pull her out of school. Sign her up for homeschooling. You may have to take her to school for yearly testing. So she doesn't miss out on socializing, you can place her in after school programs-then you will be able to gauge her good and bad days as to when to take her.