Don't give this moron another thought. You would have better luck reasoning with a two-year-old. I'm sure she will be moving on the harrass someone else soon. It sounds like your GM will just let her get away with it. So, let whatever she says, roll off your back. Just smile at her and be extra "super-nice" to her! This is how I usually get back at my annoying coworker. She enjoys making others miserable so just show her that you are not.