This is a short-short story that's an allegory about popularity and fitting in and the brutality of little girls. This is the sort of short story they should have kids reading in elementary or middle school, instead of the dull crap we usually got in our middle school reading anthologies; I think it might make an impression even on tweens. Go check it out on
Tor.com; it will only take a few minutes to read, and it's a Nebula nominee.