Hello Dinlaw

Sorry to hear you've had to deal with odd behavior from your MIL. BPD is a confusing and sometimes painful disorder. Where did you hear about BPD? What behaviors have you been seeing?
the wounds and wasted energy this has caused still run deep. What should our next steps be?
We all understand how painful this can be for family. Taking care of you is one of the first steps. How have you been coping with your MIL? Learning more about BPD behaviors and how to better communicate can help immensely.
Looking forward to hearing more of your story. Keep posting, it helps.