I guess the teacher is fending off heaps of upset parents. But it does seem odd given her previous marks that she wouldn't be in the top quarter. Are you friendly with the teacher she had last year? If so you may be able to approach him in a sort of - I'm confused, would you have expected her to qualify etc?

But the crucial thing is has she been disqualified for just this unit or the whole year. If it is just the unit get hold of the test and help her work outhow to do better next time.