That would be a horrible idea and that would be playing right into my mother’s hands. My mother has been gaslighting me my entire life and she has been lying about me to everybody around her by stating that I have a severe disconnect from reality for my entire life. One of the few times in her life she was ever honest with me was when she told me she resented that I was not a miscarriage like the doctors told her I would be. She gets off on acting all calm and then pointing at me when I have a visceral reaction to her lies and then she starts telling everybody I am crazy.
I'll be totally honest here: This actually sounds like MORE of a reason to go and just get super annoying.
Go there, irritate, cause a freakout from her. Sure, she'll yap alot... but imagine what anyone watching will be thinking? Someone that fired up is going to start getting on everyone else's nerves. It'll eventually ruin everything for everyone there.
Who cares if she tells a bunch of jerks that you're crazy? You have no desire to interact with those dolts anyway. Maybe it'll get them to want to deal with you less. Sounds like win-win to me.
Bonus points if she gets so riled up that it makes HER look crazy. Based on what you've said, it doesnt sound like it's a very long or difficult process.
Or... better than any of this... simply say "no" and leave it at that, ignoring her the rest of the way.
One way or another this is like so many other problems in that until you bloody well stand up and DO something about it, it's not going to go away. I doubt you want this problem to just keep repeating... yeah?
You've got options, but it's up to you to actually DO any of them. However, if you dont do any of them... well, she'll win, now wont she? She'll win now, and she'll win later, the cycle just repeates. EVERYTHING you've said makes it sound like she's pretty much a schoolyard bully, and the act of caving in to a bully's demands IN ANY WAY is exactly how they get an edge on you. If you want that, then by all means, dont fight back.
You can either take a stand in some form, or you can lose to her. Up to you.