Hi,
I think this is a very good text in terms of content because here is an unhappy person saying that she needs to reach out to find some peace ("I need counselling" I think it is also very positive that she is voicing some of her problems. How I wish every unhappy person could be brave enough do this.
Is this a good thing in terms of your relationship? I wouldn't know. I think, realistically, that could only be decided retrospectively. That is, after some other things have happened. If they are good things, then yes, I would call this good and vice versa. The rest would be prejudiced or informed guesses.
This may be a step towards recycling, then the common experience is obvious. Or it may be an opening to a happy future. In either case, if she has BPD, then this may mean that she is a bit more relaxed at this point.
What would I do at this point?
I think I would prioritize how I could help this person access healthcare that she says she needs (counselling). I wouldn't turn this into a more intimate or personal conversation that could distract us from this goal. Neither would I bring this help as a condition for any kind of intimate relationship. I wouldn't pressure much, either. I would particularly avoid exaggerated statements about how "wonderful" it is etc. They might be scary. I would remain calm, collected and available and try to help her take concrete steps toward counselling.
I wouldn't think about the rest for now. (I would want to think about the rest like crazy, but would say one step at a time to myself

)