Hang in there it will be over soon! Roomies can be soooo frustrating! Just sit her down and ask her not to get in the way of you training your dog. Well not so blunt, but talk to her first and tell her you don't want to fight. I think the best way to avoid a major conflict is to be open about your feelings. Otherwise you will end up blowing up
Who knows maybe more good will come out of it than you realize.