Seriously, this could have been written by my mother. I have emails like this in my inbox right now. Here's where my time at SR has been a blessing and allowed me to detach more from this kind of crazy.
*IF* you decided to respond, I would say,
Mom,
Since you decided we would not do Thanksgiving together, we made other plans.
Thanks for your consideration,
WTBH
Don't respond about the rings, don't take the bait. She sounds like a sabotaging, controlling person. I'm familiar.
xx