The Glaring Girl

There she is again: the Glaring Girl. She sits in the front row in my class and glares, but I can't tell how to interpret her expression. Is she disgusted with my teaching, contemptuous of the material, or simply accustomed to greeting the world with an angry glare? I don't know how to find out, either: "Um, excuse me, do you hate me personally or is it a more general contempt? Or is that just your usual look?" I find myself avoiding her glance, looking right past her, teaching to the other side of the room. What is one to do with the Glaring Girl?