Different females behave differently. I have been fortunate that even with the sick or dead puppies, my older female just sets them aside/apart from the litter and ignores them. Makes a quick and easy pick up for me. Two litters ago, one pup(male) was extremely small and weak, and I wanted to intervene and take it to the vet. Everytime I reached for it, the mother would gently hold it in her mouth(holding her head erect and proud) and growled when I tried to take it from her. Whenever I came in the room, she would snatch the weak pup up and hold it in her mouth, with a far away look in her eyes. After 2 days the pup died, she set it aside, and let me pick it up and take it off without any resistance. My mentors have told me I have been extremely lucky. They have had dogs that have chewed up entire dogs(like yours), or chewed off an arm or a leg, only. One had a female that picked up the pups by the rear and smashed the heads on the floor(After chewing the cord off), killing every pup of a litter of 5, after each was born. I agree with the sixth sense or keen intuition of the mother, "knowing" things that we can not see on the surface. Good luck with the whelping process. Hope you have a healthy litter.