Emily, hon, act like her mother. Sit and "talk to her" and tell her that you all will be going to your parents for Thanksgiving and that Daddy will be staying home with his family. Tell her that you would really like her to come along, that you will be having lots of fun with her grandparents and family and everyone would love to see her.
Tell her you are treating her like a big girl and that you would like to know what she wants to do and whatever she chooses is OK with you. (AND MEAN IT!)
I don't know how your relationship is with your daughter, but it sounds as if she is just a pawn used with the power struggle between yourself and your husband.
Stop agonizing over every single decision you make. Make your decision and stick to it.