It is normal for a ***** to eat a dead puppy as part of the nest cleaning instinct. Also a ***** should be given a warm dry quiet place (whelping boxes in the house where you can see and hear what's going on, are the ideal situation. In good kennels, dogs at least are taken to whelping boxes or stalls in a special area that is away from the rest of the dogs and activity.) to whelp and care for her puppies in. Make sure that the whelping box is large enough that she can turn around and lie down without squishing pups. A guardrail around the inside of the box is often used so the pups can get under it, which helps minimize squishing. Some females jump up and down when excited about getting to go out, when they hear another dog, etc, and may step on pups and accidentally hurt or kill them. It is very rare for a ***** to eat live pups, those that do that I know of, would kill, dismember, and eat their entire litters if they had a chance. Such bitches should not be bred from and in at least one case I know of where the owner of such a ***** saved a daughter and that daughter of the killer ***** was raised by another mother, did the same thing when she had pups. So there is some indication that such a behavior might be hereditary. However, it doesn't sound like your ***** is that kind of dog. It sounds most likely that a pup died for whatever reason (and its not uncommon at all to lose newborn pups, especially in litters that large), and the mother ate the dead pup as part of her nest cleaning instinct. I hope you had the mother checked by the vet to make sure she didn't retain any placental material, and to make sure her uterus is recovering normally after the whelping. Also have the vet show you how to check for mastitis, another common problem to run into with dogs who are nursing puppies.