What an unfeeling mother, DIL is, Nan! But that just tells me she wouldn't be very good at comforting the boys, anyhow! TG they have DS! I hope he goes for joint or full custody.
I agree w/ Yoga. Please be as supportive of DS and GC as you can (w/o antagonizing DIL, of course, as that could backfire). The divorce may take longer than you'd like because DIL is dragging her feet - and because the courts, too, often drag cases out, I'm afraid. But, eventually, everything will fall into place. (((Hugs!)))