Sorry the update has taken so long!
I finally talked with the mama in question (I wasn't really able to hold a conversation for a few weeks without crying), and in the end I feel very sorry for her, and not so sorry for myself.
This is really a case of her husband over-reacting, and asking her to cut off the friendship. She's having some problems in her marriage, and is trying to get her husband to see a counselor with her, and she would rather not make this a huge issue right now. It turns out that she's lost many friends before the same way (not necessarily involving the kids, but with her husband over-reacting). I don't know how I'd get by in that kind of marriage. I really like this guy, but the more I get to know him/them, the more I realize that he does need some help.
I started coming out of the PP hormone crazies at about 6 weeks, and I feel very much myself again. I have also started seeking out new sources of friendship, and that has helped in losing this friendship.
So, I HAVE left the group, but the group was really only the three of us, and I was never that close with the third mama.
You know what I'm sad about, once all is said and done? I shared the excitement of this pregnancy with these women, and now they're missing out on watching my super-cool little girl grow up.
But at least I feel like I again have the social outlets that I need, and am building new friendships.
Thanks for all of the hugs!