“Haven’t spoken to future SIL since the blow up dinner in August but she made sure to send us a text letting us know that she got the save the date (yes she is still invited) and that we are adorable. Well, yeah, we are, thanks. But are we just going to pretend you didn’t call us terrible, horrible people that were ruining your life? Is this your way of apologizing? MofV and I are baffled and simply responded with a “Thanks” text.”
I would consider accepting this as much of a peace offering as you are going to get and taking the high road and inviting her. You are going to be dealing with this lady for the rest of your life. Your kids will be cousins with hers. She sounds crazy but you are stuck with this relationship forever.