Please don't feel guilty!

I have an explicit example of no contact in my family because my father abused me and spent some time in jail as a result. Making the decision to cut him out of my life (and my future children at that point) had an obvious reason. I did try for a while before that to give him a chance to turnaround and prove himself. But once I was satisfied that was never going to happen, I cut him out. I grieved the relationship I never would have, it was almost like a death without any public recognition, so quite lonely. But I have never regretted it, not once. It was the right thing to do.

I would readily do the same thing with MIL, but it's not my decision to make, it's DP's. IMO, risking the kind of emotional abuse that has damaged DP just as much as the sexual abuse in my family did me, to my children is not an option. Hence the limited and controlled access. If it escalates again or she tries to involve our children to any unacceptable level, we will walk away without a backward look. At least DP has me to understand if that happens. Thankfully I think she's getting old and desperate enough to toe our line a lot more than she ever used to. For the moment...