I think that if you take on the responsibility of having everyone over, you are going to end up having to also put up with any drama that ensues. I don't think it's avoidable from what you describe. You mentioned new traditions, why not start a tradition of going out to dinner, so even if she shows up, she may have less of a chance acting like a total idiot in public
. Or just have a small intimate dinner with your husband, and then go over to the 'rents for dessert. These are probably very unrealistic options, but with them said, I guess my point is that until someone intervenes and people get offended you are going to get stuck dealing with this mess.