Oh, J., this just breaks my heart! I can't believe how open people are with their opinions on how YOU can raise YOUR own kids! I have the same problem, and my kids don't have bipolar or anything else (I don't think...lol), but it just upsets me so much. They are so ignorant and have NO idea how hurtful that is to a parent, especially about their own child. People can be so rude, and then, to think that their kids are "angels"...ugh!
Sorry, but I just think it's so rude for any person, parent or not, to make such rude comments to a parent. And it's not just with words but with body language, too- nodding their heads in disapproval or widening their eyes in "shock" at how your child is "acting".
It's so hurtful and painful, and it really hurts me to think that someone is judging my child based on what they see in just these few moments. They have no idea of all the other wonderful things they can do or say. They don't see the beautiful people that they are when everything is "normal" (no kids teasing or what-not). But I try to point these things out, when I can remember. Sometimes, I am just so taken aback at others' reactions that I can't say or do anything but just pick up my children and walk away.
I wish there didn't have to be any explanations, because people need to learn to live with and accept others. I mean, we're expected to accept rude people, so they need to accept nice people. lol
Could you, possibly, change the format of their playtime? Maybe you (or the other mom that's watching all of the kids) could determine the game their playing or activity their engaging in. Try to include some that your daughter's really good at and enjoys...this way, they can focus on the good in her and see her at her happiest. :)
Is there any obligation to keep watching the other kids? I mean, are you being paid for this? Are you the mom's friend? Is there any way to just take your daughter to an art class, gymnastics, or anything else? Just curious. :)