@thebird I can sympathize.
My wife cut off her mother about 5 and a half years ago, when our second child was about 6 months old.
MIL was/is a malignant narcissist, and I supported my wife's decision wholeheartedly.
It's been more than 5 years of pure bliss. No more holiday craptaculars. And no more having to put up with her coming over unannounced.
I remember when our first child was a few months old. My wife was changing him and, for whatever reason, that offended her mother, who ended up calling my wife, her own daughter, a bitch.
I took her by the elbow and walked her out of our home, thanking her for stopping by. She tried to force her way back in, but palm-pushed her in the chest, and told her that her visit was over. She was in a time out for a few weeks, but she also realized at that point that I had her number. She was a bit more careful with her attitude after that, but would sometimes slip.
I never pushed for my wife to cut her off, but when she decided to do so, I will confess to throwing myself a little party involving a cigar and some fine single malt scotch.