Hi V.,
Some people are just clueless. I don't have a better explanation for it. They just *are*.
It sounds like you know your own feelings and that you aren't getting what you want from these relationships. Aside from asking you "Is there anything you are/aren't putting out there which might influence this", I don't have any fantastic advice.
I've been where you are to a certain degree, and I know it's not fun. I also realized that this particular group of women were not going to be discreet about what they did because *they* didn't feel they were doing anything wrong. I didn't know where the disconnect was, and felt bad about it too. Over time, though, I have realized that I'm okay with this. I think we just have very different personalities; I'm pretty type-A and like to plan ahead and they are more laid back and very spontaneous. Nothing wrong with either way of doing things, but realistically, those two types don't always fit easily. Some of them also, I think, needed each other more than I was needing that group, if that makes sense. Not saying that in a judgmental way, but more of "just where we were in our lives" way.
The complexities confound me, sometimes, as well. I have learned to just accept what people have to offer, to offer what I feel good offering, and to find other ways to have my desire for friendship fulfilled.For me, this was making an effort to stay connected with old friends who I had a good history with.
That said, that one friend who I had a deeper connection with in the group-- that's where I make a concerted effort. So continue to put your efforts there. Continue inviting the other ladies IF you want to, and maybe even expand your circle of moms so that some new women are invited. I did find that my son's preschool and school aren't great places to make long-term friendships. I'm not saying it doesn't happen, but that from feedback other moms of older kids (high school age) have given me, it is the exception as opposed to the norm.
I hope you find a way to feel better about this and remember-- this likely isn't about you.