See, if you were American you would have been forward enough to find out. Show her this panel next time in class and ask her what she thinks. At least it might get you talking. At best, you have someone to talk with who shares a culture. At worst, because you are half expecting it, she will look or say something rude, and you're no worse off than before.
I was kind of thinking the same thing. I should just buck up and talk to her...argh!