My experience with rats is still relatively short, but I've always been told (and my experiences follow this) that the moms won't harm healthy pinks. Neither will males. It's all part of their family order. If the moms (or dads) ate them, there was probably something wrong with them, that the human couldn't see.

The stillborn litter--has that mom bred before? Perhaps it was just a "first litter" type of issue for her? Too young, or not enough of a nutrient she should have gotten? Not enough fat stored? There's many reasons why it could have happened. I don't know that I would give up on them without giving them at least another chance or two. Could have been a fluke. And you're always gonna lose a few babies. Typically out of a 12-baby litter, 9 or 10 survive, but sometimes I'll just have 6 or 7 that make it.

If they continue to have issues, you might consider feeding off a few of the less productive ones.