My D7 had her birthday party at her mom's "compound" last August. I would have liked to have had the birthday party at a neutral place and XW understood, but D7 really wanted to have it at her mom's place. I had no desire to spend any time at their place. I have been shown the kids rooms but that was uncomfortable for me to go into their place.
FFG's XW sounds like a real prize. How many XH's does she have?