As the mother of a 5 year old and a 7 year old, I say...serves the kid right. Of course, I would only say that if no one was seriously hurt, because no one deserves to be seriously hurt. But it sounds like no one was seriously hurt, and I am truly glad both you and the girl (and your bike!) are OK. And since you are all OK, let's just hope that she learned a valuable lesson and will follow the rules better in the future.

I am by no means poo pooing your distress. I would be freaked out too -- particularly by the what ifs. But it sounds like this kiddo will not be worse for wear, so try not to dwell.