Welcome Wednedsay: I'm sorry about your situation. What are some of the behaviors your daughter exhibits, that lead you to believe she has a personality disorder?
My sister is undiagnosed, but I believe she is a high-functioning BPD. My niece, who supposedly is being treated for PTSD, likely is BPD (in my opinion). I'm not in contact with my sister, but I have met up with my niece on a couple of occasions. Although my niece and I have spoken about specific behavior issues with my sister, I have never mentioned BPD.
It generally doesn't go well, when you try to give someone a label. What was your objective in discussing your daughter's mental health with your niece?
The Karpman Drama Triangle workshop can help you learn about healthy triangles, versus unhealthy ones. Check out the link below:
KARPMAN DRAMA TRIANGLEhttps://bpdfamily.com/content/karpman-drama-triangleYou may need to let some time pass, before you contact your daughters. You can't change anyone else. What you have control over is yourself and how you interact with and react to others. It could be good to spend some time learning many of the tools and skills on this website. There are some helpful links to the right of this post and the two links below are helpful skills to use:
VALIDATIONCOMMUNICATIONS OVERIVEWLet us know what you think about the info. at the referenced links. Jump in and ask questions.