And we have also had the direct "We are all doing this NOW and you are expected to do it too" situation where she will just stand there, say, watching others pick up trash...and it's frustrating the other adults, which in turn makes me sad.
Out of curiousity, have you asked her why she will stand and watch others do something and refuse to participate? Once you know the why from her perspective - whether it's as simple as that she didn't want to or something more complicated - you can begin a dialogue that logically walks her from her own driving motivation to not participate to the logical consequence to that choice. I know for my kids that when empathy, desire to fit in, etc. were overridden by another stronger motive, once they understood the consequence, such as not getting to be independent and go with other kids to group events, they were more willing to do what was expected.
