I am lurking and here to offer moral support. I'm not so sure I have any good advice.
I guess if I were to get into a talk with her about not enabling your friend's D, I would say something along the lines of, "I know you want her pain to end, but moving her closer to D will create many *years* of pain for their children. Tearing a family apart is serious business, and I don't think any of us should be advocating that for them right now."
The trouble with having an open mind is that people put things in it.
My sitch - Divorce Busted! http://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=1804137#Post1804137