I think we could go nuts trying to figure them out. But, she is home. Step one. It sounds like you have some very real expectations about how she should be behaving, as a wife, a mother, a friend, a lover. Possibly she is not ready to fill all those roles at the moment. Or feels that she can't live up to those expectations so why try.
I agree with Kitti about the ephinany part, at some point I think it comes for them, until then, what are you doing to nuture the friendship, just the friendship, without expecting more. Should you expect more after all the years of marriage, I think most of us would agree yes, but that isn't the reality of where we are in our lives.
You can say no to her invites if there are things that you want to do, if you are going to resent going somewhere with her because you can't do what you planned, don't do it. The resentment will make start to seep out in ways you don't realize.
You seem to be doing so much for everyone else: children, work, wife, but how about you? Just for you, carve some time out that makes you an interesting person to yourself.
