I would be cautious here. Randi Kregger in her book “Stop Walking on Eggshells” gives this advice:
“As you read this book, you may be eager to talk about BPD with the person you think has it. This is understandable. Learning about the disorder can be a powerful, transformational experience. The fantasy goes like this: the person will be grateful to you and will rush into therapy to conquer their demons.

Unfortunately, the reality differs. Family members repeatedly told us that their loved one instead responded with rage, denial, and a torrent of criticism. Frequently, the person with BPD traits accused the family member of being the one with the disorder.”
Good luck.