I read the "So What Happened" as well as the post. Let's see -- you say you're independent, don't ask for help, etc., and let's assume she knows that about you. Yet you're feeling peeved that she doesn't visit more or cancels visits. Pretty mixed signals from you about what you really want and expect from her.
She likely feels like she's giving you space; that you do invite them but maybe she cancels because she fears your invitations are "just to be nice" and not really meant wholeheartedly; maybe she feels it's your husband behind the invitations and not you, and she fears alienating you; maybe she realizes or at least believes that all her attention during your pregnancy was unwelcomed by you so now she's backing off.
If you say "I thought you'd visit more, why haven't you?" that would really confuse her, I think. She's seen the baby once a month since birth -- that sounds just right for many families, I think.
I think she may be confused about how much space to give you. And I think you sound a bit confused yourself about what you expect: Visits only on your terms, no help or advice to be offered? If she took up every single invitation you have made, would that total of visits really have been a bit more than you'd want? I'd think hard about what you really expect from her. Continue to invite but be clear that you really want to see her. But if she begins to come more often, don't change your mind and start being cool toward her because she's interfering with your independence.