Although I totally agree Carol was inappropriate with her charity solicitations, I am also starting to wonder a bit about Madeleine. Was she planning to go to the play before she knew Carol had anything to do with it? If she was going solely hoping that there would be something else awful to tell about Carol and Connor--this time occurring in another venue, nothing to do with Carol's job--it starts to become a bit uncomfortable and gossipy for me.
I wonder why Madeleine walked over to Carol near the end of the story. I would think the situation would obviously be rather awkward and uncomfortable, with Carol giving no indication that she wanted to interact with Madeleine. A polite nod or wave from Madeleine's seat would have been better, I think, and Carol could have walked over to her if she wanted to chat.
Regarding the end of year meeting--I am also wondering how that will go. Is Carol expected to be present? I think it would be a really difficult situation--people standing up and saying, "Carol sitting right over there did this and that bad thing," Carol sitting there listening to it and getting upset/defensive, management trying to calm everyone down. I'm not sure what good that would really do, if that is indeed the plan (which it might not be). I think it would be better for management to talk to volunteers individually or at least in a small group without Carol there, then get Carol's side of the story/discipline her privately.