I do not think a child needs to go through this kind of treatment, if given a choice. UNFORTUNATELY, this is far from rare. This is that girl-type bullying that is just evil, but, like I said, not uncommon. Bullying (especially of this kind) will never totally cease...
It isn't necessarily bad that you reported it, but unfortunately it isn't the kind of bullying that is obvious to teachers and other parents. It is the sneaky, less noticeable kind. Therefore, it is hard to detect and stop. Honestly, I think a lesson to your daughter would be more effective in this situation than telling their parents and such.
Helping her know that this will happen in life -ALL the time and to learn to deal. To tell her that she can still talk to you and her friends about it (I told my daughter that she can also talk to her friends about this one girl who is a borderline bully, and that simple suggestion helped her tremendously). Expressing yourself is a form a therapy. It is empowering. Let it all out. I also encouraged her to let the girl that was bothering her know that she didn't like what she was doing. She can speak up. Another thing your daughter can do is show the teacher where the jacket was placed. Have her say, "They put my stuff here again!" as she gets it back- in front of the teacher.
Make sure she knows that she can say something just as much as you can. But also, more importantly she needs to know that stuff like this will happen again, with a different person... and helping her have confidence to deal with it is the best thing you can do. Help her change from victim to overcoming and moving on.
Anybody here that wasn't bullied by girls like this? The manipulative, sneaky hurtful actions/comments? I have yet to know a female that didn't have to go through this. There are plenty of adults like this (it never stops), and I just make it mean nothing to me- it gives the b***h less "power".
You telling on the girls hopefully made a light bulb go off in these girls' heads that they took things too far and that they were being mean.