Hi flygirl1986. It sounds like you are in the middle of a tough family situation at the moment, and I am very sorry to hear that things are so difficult for you right now, but it is great to see you reaching out for advice. Am I correct in assuming from your post that you, along with your ex-sister in law, are diagnosed with BPD?
This site is a support group for those who are, or were in a relationship with a person with BPD, so many of the posts can be triggering to a BPD sufferer. There are other resources which can assist you and who may be able to offer some useful advice. Please check out:
Resources for BPD Sufferers.
Thanks for reaching out to our community and I hope you can find resolution to your family issues.