Sorry to hear about this, DLE. Your family has suffered so much already. I did some reading (in addition to your link.) It seems it is a very difficult disease to properly diagnose, and there IS much political and peer opposition to treatment. Apparently, there has been alot of corruption/graft involved in SOME treating organizations. This is extremely unfortunate when people's lives are at stake.
If you haven't already found this article on the internet, you "might" find it at least informative, if not supporting of your position.
Lyme Disease: Questionable Diagnosis and Treatment
I wish your sister and your family the best. I hope there is something that can be done even at this late stage.
Hobo