G.W.
Ok, here's what I would probably do. I've done it before when a problem arose with my daughter and her "best friend" and it worked out well. Invite the friend over to spend the night one Friday or Saturday night. Then, simply get the girls alone together and casually bring up the subject that you hear they are having some problems at school and we need to figure out how to make it better. Don't act mad or accusing, just be calm and matter of fact. See if you can get the little girl to talk about what bothers her and then have a good three person heart to heart about real friends and respecting. I'd end it all by gently saying that if we can't get along then we may have to take a break from each other at school for awhile. It may help this little girl to think twice since she knows that you know what's going on. And believe me, she won't run home and tell mom what she's been doing so you can feel confident it will stay between the three of you. There's just something wierd about a seven year old biting, that's just way too old for that kind of behavior...