Make sure the counselor knows about this. I understand that the kids are innocent victims of Mom's buyer's remorse, but that doesn't make the buyer's remorse go away, nor does it change how Mom responds to it. *Mom* has to be the one who decides she's going to act differently. You can encourage her up to a certain point, but beyond that, it's up to her.
Be careful that you do not inadvertently martyr yourself for the sake of behavior change by your wife, change that you may or may not ever see. Even if she does change, you could end up resenting her for the sacrifices you had to make in order to get her there. You are "pulling her part of the train," as well as pulling your own.
You are very concerned that the kids aren't getting the mother they deserve, and that's what you need to make very clear to the counselor. That's how it looks from where I'm sitting.
Love means never having to say, "Put down that meat cleaver!"