Hello SadBPDMama, really glad you found the group. We get it here, that being a parent to a child with BPD, even though the child is an adult, is exceptionally difficult and rarely straightforward.
Couple of questions as we get started:
I have just learned that my 36-yr-old daughter most certainly has BPD.
Is this something that your D36 shared directly with you, or did you learn of it a different way?
If it is something your D36 told you, did she mention anything else at the time about privacy preferences, etc?
He does not know of her new diagnosis.
Just confirming -- it's an actual official diagnosis, correct? Versus -- she said something like "I sure seem to fit the BPD diagnosis criteria" or a mutual friend mentioned "if anyone were BPD it'd be her"... just feeling out the "official-ness" of the situation.
Not that "official diagnosis or not" matters that much for how we interact with the pwPD in our lives, as it's behaviors/traits that are challenging, not the specific label. More asking to get a sense of your situation.
As you think over your previous and current relationship with your D36's dad (you mention being on generally cordial terms with him in the past), what do you think would happen if you did tell him -- what would happen between him and you, between him and D36, between you and D36? What might happen that'd be positive? What might happen that would be negative?
This board is a really good place to "hypothetically play out" our choices as we navigate the tricky territory of having a loved one with many PD traits.
Again, welcome, and we look forward to hearing back from you;
-kells76