I know that what the other employees did was wrong to you, but I'm not sure quitting is the best idea. Remember, you ARE being appreciated!! What you have written about these kids show that they truly appreciate you and are glad that you come to them! Maybe you could make the suggestion that your boss come see you in action? Or even have your boss talk to the kids! I feel like if you like your job so much, without all the snobby drama, and you like the kids and they like you, maybe this is one job worth fighting for?

If that's the road you chose, then try to go to the meeting calm. Let them know you were angry about the untrue things said about you and that you didn't know what or could even understand why they were saying these things about you (which I'm assuming from your post, you didn't). Try not to get too defensive, even though you're (very rightfully!) going to want to.

I'm not trying to push you to stay at the job especially since if you do stay, things could be awkward with your coworkers, but I just want you to remember how much the kids like having you work with them and how much you like the kids back. But you're not there for your coworkers; you're there to help kids.

Take care! I hope I didn't offend you; I'm sorry if I did.