Lol I'd have flat out called her a cunt in front of the class. That is the kind of thing that you shouldn't let embarrass you. The only person who should/would be embarrassed is her. She would be the anomaly not sleeping or disinterested at that hour. Classmate presentations typically blow (that is why I make mine absolutely insane) so you did bothing wrong. I'm sure the class figured she was on the rag or something - nobody does that lolz