Ah I see
Well I don't think you should let that stuff get to you. Just ignore it to the best of your ability. Instead of being mean to this child, just simply ignore it. Now I'm not on her side cause we are friends because I can see where you are coming from but it's not that serious. Now if she was saying rude things or what ever it would be more serious but it just seems like you're letting something get to you that is very avoidable.