Sorry to hear that you are dealing with this. As Phlosphr pointed out, Borderline personality patients are known to be very frustrating for even the trained professionals to deal with, so it is no wonder that you’re so upset about this.
Did you see this thread that was posted a while back by other people with borderlines in the family? Borderline Personalities and Familiy Relationships - In My Humble Opinion - Straight Dope Message Board
I’m sure that it’s hard to see a loved one making such mistakes, but she needs to want to get better. There is only so much that you can do for a grown adult regardless of how much you love her.
What did the shrink suggest instead? Perhaps it might be worth trying to talk her into something like an IUD? As disturbing as it is that she is with the Jerk, perhaps there is a silver lining to it in that he may not want to start over with another baby at his age, and that might be the main reason she hasn’t turned up pregnant yet.
Until I read the OP’s response I didn’t know squat about the Jerk’s dad.
He raised this man, and sometimes the apple doesn’t fall far from the tree.
I gathered that the Jerk’s dad was OK with his (36 year old) son dating a 16 year old and I had this picture in my head of, you know, of some dirty old man with no morals.
The last fricken place I’d end up if I was dating a 16-19 year old would be back at my dad’s house. I’d have to stop at the emergency room to get the shoe out of my ass.
I’m glad the OP thinks the Jerk’s dad is a non-threat.
She’s had several appointments made with the health dept. to talk about her birtch control options. She blew them off so many times that they won’t give her another appt. She claims to be using condoms, but I don’t know how consistently she uses them. She’s been on the pill, but she’s no better at taking them every day than taking her other meds. I think an IUD would be great. I wonder if you can buy a do-it-yourself kit on eBay?
I meant to address this earlier, then got distract-ooooh, look, shiny!
Anyway, we’ve been involved with a lot of professionals over the years, and every single one of them has told us that they don’t see that we’ve done anything wrong at all. She’s just ‘broken’. I did write a somewhat angry editorial in our neighborhood association newsletter about parental blame, though. Everything you see about how to raise a good kid seems to give the same message: kids whose parents raise them right don’t end up doing drugs, drinking, smoking, joining gangs (yeah, she did that, too), dropping out of school, on and on. I know as well as anyone that being an involved parent helps. But I wanted to put the word out there that you cannot assume that every juvenile delinquent you see is the product of an uncaring home.
It’s just possible that she does already have an I.U.D., but, you know, she likes to provide something to worry you. OK, perhaps not, but it’s a possibility.
And it all sounds altogether dreadful, so I hope you and the rest of the family do get some good times without being under constant pressure like this.