I don't think she has a chance in heck of winning this motion. H will call our L after the motion is filed and we get copies. I am going to spend time this weekend pulling out the documentation I already have specific to mental health so we can send it to our L so she can decide how to proceed.
It's sounding like this might go nowhere, but I really understand the frustration of having to deal with it at all--and the possible anxiety of "what if it does"...It's good that you're doing some prep work just in case. I find doing that helps me, too.
What I can tell you about my experience with therapy for the kids (especially D11) and family therapy is that uBPDxw has definitely had it out for D11's previous T. Ever since it became clear that she was not going to just "fix" D11 into complying and accepting uBPDxw's inappropriate behaviors, uBPDxw has been questioning her qualifications and even threatening to file a complaint to the licensing board. She tried to make it a requirement in our separation agreement that then-D9 stop seeing that T and start with a new one. I was able to argue that the established therapeutic relationship was too important during a time of major upheaval with the family going through divorce, so she lost on that point...at least until the eating disorder behaviors began, at which point we needed to shift to someone with a different expertise.
I did agree at that point that family therapy would be needed in order to attempt a repair between then-D9 and uBPDxw. If we were where we are today and had not yet already been engaged in family T--and certainly if we were where you describe with SD13--then I would say no way to it. But back then, it made sense to try, and at this point it still serves a purpose even though for the moment the focus can clearly no longer be D11 and uBPDxw's relationship. uBPDxw would never agree to any family therapist that I tried to propose, though, so we had the benefit of having our PC appoint one.
It doesn't look like it's going to come to that for you, but of it does then I would hope/advise that:
1) A neutral third party be appointed to select the provider
2) Release of Information forms get signed so that the family T can communicate with all therapists working with any of you throughout the process--especially SD13's T and uBPDmom's T (I'm guessing she has one?)
The family T's focus will be on the entire family system. Talking to and working with each of you individually would be important, but I have found it equally critical for our family T to speak to other clinical professionals involved in the case. It helps shine a light very quickly on inconsistencies, information gaps, etc. Plus, any work the family T may do would probably have an impact on SD13, and being in contact with her T would help to navigate the least damaging path. I say "least damaging" since "most effective" just doesn't fit in these situations...just like with my D11 and uBPDxw, it doesn't sound like there's actually any chance of repair there, so the question would be how to contain things as much as possible to get SD13 through it.
I'm sending positive thoughts your way in hopes that this just goes away for you!
mw