Marie, you show a lot of self introspection and wisdom here. I hope this trip turns out well for you. You may have to ignore the complaining or do things on your own at the resort or house. This person might be invited as simply the only one Nancy could find other than you to help pay the rent on the house. She sounds like a bore, frankly, and maybe you can keep your good spirits up anyway. I have a friend, well an acquaintance, like this and I write down things to say when I am going to be around her. Thinks like, lets not talk about blank, it is such a bore. She goes into negative politics and says dreadful things. I find I have to speak up and say no to her. It makes me kind of on edge. Anyway, I sure hope you enjoy yourself.