L.B.
I dont think 3 is too young, my 3 yr old has been going since 2 weeks after her third birthday. She had a few problems at first too, but she and I kept talking about it and kept communicating with the teacher and now she loves it. It sounds like that little girl maybe having some problems with school, like possibly being bullied by some of the other kids, or something along that line, to make her suddenly hate it. I would have the mom talk to the teacher more and have her tell the teacher to be more aware of what possibly could be happening to her girl. You could too talk to the girl and see if you can get her to tell you why she hates it. Good luck!