This was yesterday, but since i was too busy to post then... On Saturday, I had "the talk" with my brother, who I knew would be supportive. I was less certain about his wife, but told him that although I was trying to keep my coming out under wraps at this point, that it was more important to me that the people I did come out to had someone to talk to if they needed it. So I told him that he could decide when and whether or not to tell her about it.
We took a trip to a museum, with his family and me and my kids, yesterday. As we were getting everyone in the car, she told me that he told her. There was a brief moment of silence and she told me that she was absolutely happy for me and that they would be there and give me whatever support I needed. She then invited me for a big hug, which is probably a first between us, and that was that.
So now I'm up to (I think) 6 for 6 of people I'm out to who were awesome and supportive (not counting therapists, doctors, etc). Lucky, lucky, lucky...