Do the same back to her, of just stop her in the hall and be like "Okay look, this has been going on for too long and I'm sick of it. WHAT is your problem? Let's square up right now, or leave me the HELL alone."
I know you hate confrontation, but I think she's picking on you because you're being passive and taking her crap. You're an easy target; she knows she can get away with it and she wants to be a jerk to someone. Make it not worth her time to give you crap. Yes it sucks, especially if you hate confrontation (I'm the same way) but she's being a bully, and all bullies want an easy target that malkes them feel powerful to pick on. Tell her to go F herself one good time and she'll be a lot more inclined to stay out of your way.