@Siquall True, but it really feels like she's in her third year, as Yabe was seen grading tests for a third year student on the first page of the series; while I can't find anything to confirm it, I don't believe that Japanese teachers would be responsible for multiple
grades in addition to multiple classes. The whole thing got started because the principal decided that if she baked cookies for all her teachers, he'd be able to let her graduate. That really doesn't seem like something you'd tell to a second year.
Of course, since I can't remember if it was ever explicitly stated that she's only a second year (beyond calling Fujiwara; I'm talking about her actual class year (we know she's in class 3) or someone explicitly calling her a second year), I could be entirely, completely wrong; in which case, I'll stand corrected.