Does she still live at home? Because if she is, then I would say that move number one should be for her to MOVE OUT. If the university has dorms, that is where she should be. Especially if she is a freshman.
I promise, if this mother keeps her daughter on such a tight leash, she will never learn the kind of independence it takes to make it on your own in the real world.
Unless this mom wants her daughter to live at home and have to take care of her forever, then she needs to let go and trust her daughter to have the common sense of a woman.
Ok, that really doesn't help YOU at all, though. I'm sorry.
I do agree that this is something that the NM has to deal with. I think that being in a sorority will HELP the situation. I think maybe she should point out to her mom that she is capable of making some decisions on her own.