Well, she surprised me. No reason offered as to why she doesn't want to visit her own family for Thanksgiving?
In a lot of ways I agree with you Mark. You have a battle on your hands with her no matter what you do. So you may as well do what you want and go in for the battle. But boy, if you do visit her family without her, there will be questions. And whether you answer them or not, there is a lot that can be read into the situation.
But how can she even expect OM to show up to visit her, isn't he married? Surely he has family to visit on Thanksgiving too.