I have no reading materials to suggest either, for some of the same reasons fern cited. Also, other than what I learned in my Abnormal Psychology class, in the DSM, online, and brief stories on this forum (and from a friend), I'm far from an expert on Borderline PD. I think it is true that handing her a book about it could anger her, but if she ever stumbled upon one, I would think a memoir could be a good first.

I suspect that my sister's husband may have BPD. He has exhibited many of the classic symptoms. But he's slightly further removed from me than your ex is from you. My main concern about my b-i-l has been the effects of his behavior on my sister and nephews. There have been serious ones. Though your ex may be different than my b-i-l in various ways, I still think that you should be most concerned about your child right now. Your ex's behavior as an effect on them.