I really relate to the things both of you are describing, and that's a bit of a small relief in a way. It's hard to know what to do sometimes because people are just so aghast at the behaviour you just outpour a description and that's pretty much all that happens, they can't help with a suggestion as it's so not normal.
I completely agree with your comments about personality disorder. Everything you have described here is similar to what I've experienced. In her mind she is clearly the centre of the universe, and she simply doesn't understand if people don't rush to worship her, or if someone dare to say no on something. She views SD as an extension of her, and so the fact she views SD's dad contact as an inconvenience means she takes it as fact that SD views it that way also. In fact SD is very much like her father, and they are very close indeed and she needs him, she has behaviour problems if she doesn't see him for a few weeks.
I genuinely think his ex thinks she is parent of the year, in spite of her child never brushing her hair or teeth, wearing clothes which are far too big or small or full of holes, being late to everything, not having her homework done, constantly having nits, constantly being over-tired, hearing her screaming at her boyfriend in the house, trying to block her child seeing her own dad to the point she won't even comply with a court order, sobbing hysterically in front of her child, telling her child all these bizarre conspiracies. She honestly thinks she has reinvented parenting and is a victim of a terrible world plot against her, and the problem is with someone so convinced that they will pursue wrong behaviour with complete conviction, as she genuinely thinks what she is doing is morally right and the best thing for her child.
That's where we know we just will never win, because if she simply doesn't understand it's not ok to scream at people, and that her child comes first not her, what can you do with that. I have heard the same thing, her simply refusing to accept a fact placed right in front of her, dismissing it, and that lack of grip of reality you are just stuck with. We regard it as a sentence getting to the end of SD being a child and thus having to deal with this hideous twisted person, honestly that's how it is. Nothing positive comes from her she is just something we have to deal with that makes everyday happy situations hard and sad. My biggest sadness of all is that I can see she will push away her own child and that's pretty awful.