NTA, let's just get that out of the way. I just... let me see if I understand this correctly. She knew you were uncomfortable splurging on those glasses. So her birthday present to you was to steal from you to buy you the glasses she knew you were uncomfortable purchasing? Then when caught, because she was never going to tell you herself she stole from you, she explodes at you and calls you ungrateful? I get all that crazy right? Never thought words uttered by Al Bundy would be sound advice but it's the first thing that popped into my head after reading this so here we are.

Now all kidding aside, OP, run. Run hard, run now, run silent, run deep. Run like Mexican water through a first time tourist, but the key word here is RUN.