This is the best I found:
https://www.youtube.com/watch?v=iraGmA7-9FAThough I'm in the same situation as you are and everytime I try to bring up the fact that she may have a problem, things don't go well, no matter how I do it, I gave up direct approach.
I tried showing her a BPD video in our language once, since she doesn't know English, otherwise, I would have shown her the one I linked to you, she had an episode right after and stated she doesn't have BPD and that she only does what she does because I don't do things right.
If you are wondering how I did it, I did a personality traits quiz myself a while ago and mentioned her, she became interested to me surprise, so I took advantage of it and we did it on her, I was amazed on how aware she was of her actions and feelings, things that I though she would deny, she agreed. After that I decided to mention BPD, without bringing BPD or anything related to personality disorders and mentioned that someone she likes supposedly had it (Marilyn Monroe), to soften it and give her the idea that she wouldn't be alone and someone who she always likes also had it, then I showed her a video, she stopped me 1 minute into the video and had an episode. It didn't work.
I'm very interested in this as well if you ever find out a way. I'm guessing in my case, she will take years of disappointment and suffering before she seeks help if at all.