You dont have anything concrete to go on at the moment, other than a feeling, so i would avoid talking to your boss about it right now- you dont want to get labeled as a gossip or trouble causer yourself when they dont know you.
If you cant avoid working with her, then be pleasant when working together, but dont get involved in gossip about colleagues, dont let her draw you in to it. If she starts, try changing the subject, if she continues, then make an excuse to leave the room for a short while.
If you are really worried then make a private log of such events wih dates and times and witnesses. If something does happen, then at least you will have a record of actual events to refer to.