Hello Branch and

You must love your daughter very much to reach out here for help, and to want her to get effective treatment to be well. You're in good company with other parents and family members who so want to help their children.
Trying to get someone else into treatment is not an intuitive or easy undertaking, especially if you suspect BPD is involved. Understanding your situation a little more will help us support you better --
How old is your adult daughter, and how is your relationship with her (is she still in touch with you, does she seem to trust you)?
How long has she been with her partner? How is your relationship with her partner?
What led you to suspect BPD was in play?
Fill us in a bit, when you have a chance. We'll be here for you;
kells76