It's a power game. The issue is never the issue with that kind of person. It's not about the stimming or the water fountain or any other superficial issue, but about kissing her butt. She can only be happy when she's humiliating you. As an adult, I can usually walk away from people like that. When I?m truly stuck with such a person, it never ends well. The more you submit to her ridiculous demands, the more humiliating they will become. The next phase will probably include crazy accusations that she will make up out of thin air, and self-contradictory demands that you can't possibly follow.
Definitely talk to your parents and/or someone in authority, as soon as you can. Continue to be as polite as possible so that you can honestly say that you are blameless. Do not lie under any circumstances. Any snarky comment or eye rolling will be used against you. But don't expect her to stop just because you ask her to by yourself. If it's possible to change her, it can only come from someone she respects, and that is certainly not you.
Part of her problem could be miss-reading something in your body language. That's probably more common with Aspies, but it happens with everybody. It could be that she thinks it's so obvious that you already know and are doing it deliberately, and it hasn't occurred to her to say it in words. Or she could be unconsciously reacting because your mannerisms remind her of some aunt that she hated, or something neither of you can guess. Chances are, you'll never know what her problem is.
In particular, the stimming is mildly annoying to her because she is shockingly ignorant. If you need it, you need it, and it should be nothing to her. But, again, that bit of education can only come from someone she
respects. http://juststimming.wordpress.com/2011/ ... iet-hands/