Hi:
This is a tough one. You can try appealing to higher ups (Superintendent, Board). A letter from a professional stating how this class is detrimental to her could help. Perhaps she could skip a grade and then be moved up to the class beyond the one she is in now.
If she falls behind, there is no good answer.
Best of luck.
Michelle Ball
Education Attorney for Students since 1995
http://www.edlaw4students.com