mggt - you have been through it all. It is deeply sad for me when there is little response to the therapies and resources that have been given to your D. Much like my DD26. It is so much easier for her to get stoned or high to avoid feeling the feelings and having to work through the pain. She just doesn't get that it can get better. Also sounds like you D projects her distress - especially onto you as the mom. This relieves the distress for a bit and keeps them stuck, IMHO. This also keeps them from choosing to go through the pain of internalizing things that can be learned in therapy.
There are so many other moms in your situation - I invite you to also post on the supporting our BPDkids board again so we can support you as a mom. Keep up here on the legal board for support on the custody decisions for your gd.
Matt has great advice. The judge has to look at the factual evidence in deciding a case. There can be empathy for your pain, but it does not add to the case. That is why we hired a lawyer to represent us in our custody pursuit - I could not question my DD in a court without lots of tears.
Keep a diary of everything. Carry it with you or lock it in a drawer or on a password protected document on your computer. Only a few words with the date, who is there, what happened is enough. Be sure and write others that are present. Focus on neglect - leaving child alone or with others, not having adequate care (food, shelter etc), use of drugs impacting care decisions.
Also pull together a file of documentation of her previous mental health contacts - rtc, doctors, therapists. Keep this together in a box. locked if needed.
If you cannot afford a lawyer, seek out legal aide in your county.
The hardest part of my custody journey was keeping it all a secret from my DD. It just about killed me - I was serously ill by the time we filed our petition in court with immune system failure/adrenal fatigue. Now I know it was worth it, I am feeling so much healthier now. But the risk of DD leaving with my gd, as she continously threatened, was high.
Also, be aware of any truly dangerous situations with your gd, and do not hesitate to contact child protective services. If the baby is taken from the home, they prefer to place with a grandparent, esp since you already have a good r/s with the child. Would the exbf parents try to seek custody? That is something I did not have to deal with.
Please keep coming back to let us know how things are going. And hope to see you again on the parents board:
https://bpdfamily.com/message_board/index.php?board=4.0qcr