Hi Peter. I totally get your frustration with your W and hope that over the next few days she will lighten up some so everyone can have a pleasant visit.
I wonder though how much your W's guilt is playing into her inability to socialize with your sister. I mean she is your family and from your W's perspective she probably feels that she wouldn't have an ally and so why bother.
Anyway, maybe if you can find a way to help your W and sister feel comfortable then the visit will be that much more enjoyable for everyone.
Speaking from a little bit of experience, my W's parents came to visit for Thanksgiving and I was really quite concerned about how things were going to go. Fortunately my W and I worked together and W set the stage with her parents and things went much smoother than I had expected.
So maybe prime the pump a little with both your sister and your W and things can improve for everyone.
Good luck and I really hope you enjoy your visit with your sister!
Me51 W53 S17 S14 M22 T25 Bomb-9/11; A-11/11; I move out 11/11
It's easy to find our bottom, it is our top that requires cultivation.
Every rough spot adds to our emotional constitution. -Barney Fife