Question about how HPD developed in my ex

Hi lads, first-time poster, this forum has been amazingly enlightening for me.

As of now i finaly stepped into the acceptance part of breaking up with a HPD, and although the obsession is still there, all the others stages rarely kick in. I too have a confused story about my experience, might share it at some point too..

But I do have another question about how my ex's HPD came to develop. She lived in a simple yet loving family, no serious conflicts that I'm aware of, her father being a love-puppy/provider. Her mother might have HPD as well, not entirely sure as I'm not aware of their entire history but she is hysterical at times.
Not aggresive, but she does scream for no reason . This was funny at first since she just raises her voice in a weird manner for no reason, which is not a clue to any PD where I live - just a lack of education. In fact her entire family is agitated and always on the run for something, this seemed lively to me, as I was raised a more discreet and contemplative manner. They all talk about anything, all the time, without much substance, so you can see why it took me awhile to diagnose my ex (by that time it was too late).

From what I read the HPD usually develops from lack of attention/love from a family member, generally speaking, but this appears to be quite the opposite. They showered her with attention and attended her every whim, could this trigger it too?

Of course, i know all these from her own stories, which I now know cannot be trusted to be accurate..
But observing them they are a very tight group who rarely allow anyone else in (i was received with open arms though) and protect each other fiercely, even when they are at fault.

This pack-like behaviour was strangely attractive...but could contain disfunctionalities of a different nature..