Husband2014, an excruciatingly difficult part of recovery from dysfunction is that it isn't a function of information, it's a function of desire.
That is to say --
It's not lack of information that stops people from changing...
It's that they don't want to.
Increasing the amount of information they have isn't necessarily a guarantee that the scales will finally be tipped and they'll see the light.
I was in treatment for an eating disorder back in the olden days

I knew at an intellectual level that it wasn't healthy -- it's not like I was confused and thought "hey, having an ED is a healthy move!" Yet there were things I wanted much, much more than giving up the ED. I could've read papers on the detrimental and deadly effects of EDs all day long, yet my attitude was basically "Yeah... But I'm gonna keep doing it". That was it -- it was about what I wanted.
Of course, why did I want that? Because it met a deep psychological need that for a long time was too painful to meet in more functional ways (short story). No amount of information could "convince" me of something that wasn't operating at an intellectual or rational level.
So, the downside is that even if her parents "knew", having more people in her life tell her "hey you might have BPD" isn't necessarily going to push her into self reflective territory.
The upside is that you can make changes in your life, in your way of being, that can model to her what real self reflection and responsibility are like.
It's a hard road, so I get wanting to get more people to "team up" and "intervene". Yet that approach may backfire. It could be more fruitful long term to focus on what changes you can make to walk a healthy path, one where you invite (rather than force or convince) her to accompany you.
Hope these thoughts are helpful, and I'm glad you're still posting here;
kells76