Such problems we have with our AC. I may write more later. I just read your post and am thinking about it. The first thing that popped into my head was to suggest you stay out of it as much as possible. Perhaps tell her you are going to remain neutral. As for the GC.......I have GC.....sometimes all I can do is tell them I love them. I can't hug them because they live 4 states away from me.
I'll write more as I give it more thought. These were just simple suggestions.