No, unfortunately, my experience with it is with myself.
Certain things prevented me from being exactly as she is, such as a violent childhood has caused such an aversion to violence that I would never physically harm someone.
And things related to autism and anxiety prevented me from constantly acting out the way she does.
But I've thought all of the things you describe.
And I went to great lengths to avoid hurting others, by severely hurting myself or abusing drugs.
Everything is in the past tense because I haven't been like this for about seven months because I take a lot of medication and have a fantastic support system. If either of these were to fall through, it would be quite dangerous, I think.
It's what I meant about something terrible, like someone dying or nearly dying, being required to change her. I nearly died more than once and many important people left me forever before I did anything to change. And I know that during certain times, there wasn't anything anyone could have done to change anything. It's good that they left.
Does she have a Favorite Person, as far as you know? If that doesn't mean much to you:
What Someone With Borderline Personality Disorder Means When They Say They Have a 'Favorite Person'
"While a best friend can be an FP, it’s usually so much more than that — and it’s important to know the differences. To oversimplify, best friends are people you love and count on, but a favorite person is someone you have an emotional dependence on, someone who can “make or break” your day."
This is what made me think of the ultimatum idea. If her Favorite Person were able to monitor her medication usage and if they have the ability to say something like, "If I ever find that you didn't take it, I'm done. You won't see me again."
Then that could actually work, because that was my only motivation when I started taking medication. But after a while, when I saw how I felt, I wanted to take it. Now, he's probably forgotten he ever said that.
Does she self-harm or threaten self-harm or is it all outward?