Well, you now have most of the pups in better shape and fostered. That pup who's side was such a mess, would this be caused by the demodex? Or another infection? I am sure she must have been in misery and if it was that bad, well not much more you could have done with limited resources. And the terrified screaming pup does not sound normal, poor thing.
Did the mom have temperament issues too? Or was it just her poor physical condition and bad structure? I can not help but feel a pang that she was put down since she took such good care of her babies in such bad circumstances. Would good care and good nutrition have helped bring her around? I know bad physical flaws are nothing one wants to breed but as a pet, would she have been ok? Not totally sound but able to be a companion?
It's a hard line to chose life or death for any animal and I was just trying to better understand the choices you made.
But to look on the bright side, now those remaining 5 pups will get a better life.