Hi knowingmyself, I'd like to join
Sandb2015 and say welcome to the family

Your story sounds very familiar. My first romantic partner had BPD as well. The relationship was a mess and full of despair and emotional pain. When I finally got out I swore that I would not allow myself to get stuck in a dysfunctional dynamic again.
When I met my current bf he was very open about his BPD and he seemed a lot more self-reflected and approachable then my ex, but for me it was still an immediate red flag and it took me about a year of friedship to even consider a romantic relationship with him.
I would advise you to take things slow as well.
Get to know her on your own terms, pay attention how she treats her friends and how she talks about her former partners. This is usually a good indication of what you can expect yourself.
Does she seek professional help and is she aware of how her BPD impacts her and others?
Is she commited to getting better?
Considering your past experiences, which behaviors are nogos for you?
Alcohol was a big issue with my ex for example, he drank often and it caused him to get even more erratic and irresponsible. My current bf doesn't drink at all, which was a big factor in my decision to give us a chance.
I think it depends on her level of self awareness whether an open conversation about her BPD and your history and codependent tendencies is beneficial or not. If she is talking about it on social media, I wouldn't be surprised about her bringing it up with you sooner or later anyway. If she doesn't, maybe adress it in a casual manner, see how she reacts and go from there.
Does this sound reasonable?