Hi, sdp. I took a break from the board during the holidays. I have noticed that there are a lot of people "viewing" the board, but only a few that actually post.
I've gone back and read the two posts you refer to. I agree that your posts were very busy, and I was not exactly clear on what you were asking. What I understood was that there was a lot of confusion about who was taking care of who's children on NYE and where the children were going to spend the night. My advice, for what it's worth, is that to avoid confusion everyone should take care of their own kids or make their own sitter arrangements. I guess you could have stayed home and celebrated your own NY's party at home with your children. This way you would have removed yourself from all the chaos and indecision.
Regarding your relationship with your SIL... you said she has acted differently since her husband died. Well, who wouldn't? Maybe she's depressed. Maybe she just needs time to heal. My father died more than a year ago, and we're STILL waiting for my mother to act "normal" again. When I'm depressed, I find it is easier to have relationships with casual acquaintances (like SIL's bowling group) rather than family. Family is always trying to tell me how I should feel, what I should do. By what you described, it is clear to me that she still needs and wants you to help her out, but she is also sending the message that she needs her emotional space right now. I wouldn't take it personally. Put her back on your email/IM address list. If you feel like she is using you, then re-establish your boundaries. Hope this helps a little.