Trick,
Had the same experience with my mom on that matter. She was the only person never painted black by my ex, and she would still accept her. As she's 90 (with a clear mind) I'm not telling her a lot about it, but she knows she has unsolved issues about her past, to say it in a nice way.
However my ex is not allowed to set one foot in the retirement home. But I don't think she will by now.
Does BPD run into families. I think it does. My ex mother in law, has abandonment issues, was sexually abused by her father at an early age, I see some symptoms, but if it is BPD it is rather mild. There have been problems in her marriage, still are, she likes to move, now possibly to Spain,... It is not up to me to decide on that matter but it could.
My ex has BPD, no doubt about that, she has all of the 9 symptoms, but some of them are partially under control. Such as fast driving, alcohol use,... . Automutilation is in a very specific way, she hits walls furiously with her hand or fist, but almost only appears when drunk. Shopping, buying cars is a problem in her case.
Problem is that her daughter, is also very needy to have people around her, to get a lot of attention, has abandonment issues, can't cope in a normal way for kids with personal losses such as the loss of her grandfather 6 years ago, her aunt 2 1/2 years ago, even her dog over a year and a half ago and a cat 9 months ago. She is bullied at school as well. She has a number of things coming up from her mother. She even cried months later over the fact that she misses me. As she may cry over the other things in her life I mentioned. Her mother only had serious talks with her when I convinced her of the necessity in most of the times.
Concerning the problem with other BPD's and asscociation. Yes they do at first, they are people without an actual identity mirroring each other. But also NPD's as well. I was told that her husband (she never got divorced in almost 5 years) has serious narcistic features. I just thought he was a egoistic ass.
But with what I know on his past, it could be more indeed. So in that case he can't help it either.
BPD vs BPD is the hell. It starts as a miracle (my ex turned lesbian, but well her sexual identity changes with the wind it seems) and they put each other on a pedestal beyond belief. And then the other side of the BPD happens, and it turns into violence, accusing of BPD to one another, pushing, pulling, it is hell ! And still they also recycle ! They manipulate one another beyond belief. I've been whitnessing it and it is traumatising them much more I think then anything else.
The BPD she cheated me with, started a relation with another probable BPD in the town my ex lived, and moved in with her to be close to my ex ! Imagine that ! In my village she actually was telling she moved in with my ex. That same person just has been cheating her new GF just in front of her in e number of occasions, when drunk even pushed her GF from the stairs. And my ex says, she's not all bad, and recycles her again. It just shows how big the problem is in their behavior. And how they even justify each others behavior.
My ex her friends are now for the largest part BPD's, it is a terrifying thing, and I'm glad I'm not around this anymore.
Reg