I know it's not generally suggested to talk to the person with BPD about it, but I don't know what the suggested route is with family members. I would be interested in that myself. I often wonder if talking to my dad about my uBPD mom would do any good.
What would be typical high functioning BPD behavior from parent to child please?
There are a lot of posts from us kids with high functioning parents among these pages. If you're just looking for a general idea, you might find it helpful to read some. Otherwise, if you have specific questions, let us know and we may be able to answer them better.
My sister has two kids, and she displays many of the traits of BPD (whether it's just learned or she has the disorder also, I don't know). I also wonder if there is anything I can do for them.
I don't know if there is really much you can do in this situation. Feeling helpless is the worst.