What helps? Education. That is, education for those around the person with BPD (pwBPD) or whatever _PD it might be. The difficulty is that the pwBPD resists or sabotages proper Boundaries. So our only recourse is for us to
apply boundaries to ourselves. How so? Review our threads on Boundaries over on our
Tools & Skills workshops board.
There are lots of examples there. I often give an over-simplified example such as this: "If you do or don't do ___ then I will do or not do ___." Ponder how you or your children can apply
Boundaries to yourselves as a
response to poor behaviors by the mother.
This certainly won't fix everything. And surely she will obstruct and sabotage your efforts as much as possible. But over time their mother may realize there are limits to whatever chaos and outrageousness that will be allowed.
As for court, it may adjust the current custodial or parenting order (its version of setting enforceable boundaries) to further reduce or address the problems but it doesn't try to fix the parents.
From the many experiences reported here, while it is possible for a pwBPD to improve over time, the individual can't fake therapy or claim a few sessions is all that's needed. Long term therapy such as Dialectic or Cognitive Behavioral Therapy (DBT or CBT) is the accepted approach but whether their mother will cooperate with it and apply it is the determining factor.