I don't know about the merits of her argument but I’ve never heard of a lawsuit in which you sue your professor for giving you an "F" after flunking a test while having a migraine headache. Wow. I'll have to read up on the case, found http://caselaw.lp.findlaw.com/data2/circs/4th/041410p.pdf (PDF file as usual).
The law student suffers from "intractable migraine syndrome" for which she takes medication. She had a severe migraine at the time she was taking the test and asked for an extended period of time to finish it. She was denied, complained to her teacher, and exhausted her appeals with no success. After publicly criticizing appeals procedures, she was offered a second chance to re-take the examination and was told she could take it in June, but was e-mailed in May 17, 2003 that she would have to take the test on May 21 (three days later) or forfeit her chance to re-take the test. She refused, and reminded them of their promise to let her take it in June and the rest is history. She sued, claiming they were trying to punish her for exercising her free speech rights and discriminating against her because she has a disability.
The Fourth Circuit Court of Appeals overturned the district court which dismissed the case. The summary is found on pages 3-5 and the opinion basically takes up the rest). I'll read it when I have more time.
In the meantime, enjoy.
The Political Heretic