I don't think you should grin and bear it. you're paying for the same thing she is. she needs to be told directly. she is passive/aggressive and will continue to do this unless confronted. she may continue after being told. thinking she's 'cute' or something. I've dealt with people like this b4. it's annoying. if she continues, then flat out tell her to pipe down. she wouldn't have a problem telling you. Maybe let the instructor know too. but I bet the instructor has dealt with her type b4. good luck and have fun.