HEY Moselle: So sorry about the problem with your mom. It can be very painful to experience this with someone, when you need their support the most. I'm on a learning curve, but I've come to understand that some stress event can cause a disorder to rear it's head like a monster. Sometimes, we have seen some bad behavior in the past with the person, and not thought "personality disorder". Most of us have a trait or two that fits the description of some personality disorder.
My uBPD sis is the BPD in my life. She had some bad personality traits, but I was never painted black by her before. We had a 6-month period of time, during which our parent's health declined rapidly and they both passed. My uBPD sis and I were "co" everything: health & financial POA's and then trust/estate matters. I didn't know the specifics of BPD at the time. The interactions with my sister led me to seek therapy. After a few sessions, my T suggested I read "Stop Walking of Egg Shells". Boy, the light bulb turned on. After reading and interacting here, I've read similar stories.
I experienced some splitting back and forth with my sister. I was painted very black before my dad fell and broke his neck, but my sister was able to split me back to white for awhile. Then she later tried to blame me for my dad's fall, even suggested that I caused the black eye he got when he fell. I've never hit anyone in my life, although I know my sister has.
I'm in the middle of a 2 year high conflict divorce from my spouse, and I just put boundaries in to my relationship with my mother. Basically asking her not to shame me in public and in front of my my children.
Your boundary sounds like an important one. You did some validation with your mom. One option would be to just give it some time and see what she does next. Has your mom ever had therapy, or perhaps in it now? I'm thinking that some less important boundary violations are easy to come back from, but others are mandatory. The script that your mom writes to your children about you, seem like a very high level boundary?
On some occasions, my sister was able to just start interacting a few days after an unpleasant behavior - as if nothing happened. That got old for me. I reached out for therapy, when I reached the point of "no return". My sister didn't think she had a problem, nor could she talk about any of her behaviors, with a goal of talking through the problem. In her eyes, "Nothing Wrong With Her".
I find that journaling can be helpful. Is there anything you do to relieve your stress and manage it better? You can always initiate contact with your mom in a few days, week, etc. If you mom can't honor your boundary, you may have to take whatever steps are necessary to put more control on her interactions with your children. What steps might that be?