Wow...you have a mess! lol
She was eating the babies due to stress, like everyone said. Hamsters are absolutely solitary, so she and the other female would have fought horribly. Likely, they were not caged together before he took them to the pet store or all the babies would have been dead and the females would have been injured.
Now that she is in a quiet place, alone, and has food, she will probably not eat anymore. That's not a guarantee, though, especially since she already ate some. Some females will eat nearly every baby they ever give birth to, some will never do it again. Just no way of telling. Sometimes they do it for no apparent reason even when there is no source of stress.
As for her getting lost...I raised an orphaned baby once by taking pelleted hamster food and soaking it in milk and putting in with the baby. He would nibble on it. They nibble on food from the time their hair comes in at just a very few days. Eyes will open around 9 days. From my experience raising them, I think your best bet would be to give them boiled or scrambled egg to nibble on. You will have to clean their bottoms to stimulate them to urinate. Hopefully you will catch the female. I would expect she would come back to the babies, but that is not guaranteed at all. Take a bucket she can't jump out of and put smelly food like peanut butter and her food in the bottom. Put books or something going up to it kinda like a ladder. She will climb into the bucket to get the food and not be able to get out. Those traps have been very successful with all the breeders I have talked to. Good luck, and I'm sorry it's turning out so stressful for you.
If you don't have homes for the babies and your snakes will eat pinkies, you might want to consider that. I hate snakes and would never allow my ham's to be fed to them, but I have seen far too many that could not find homes. I'd hate for you to get stuck with another 6 cages to clean and animals to feed! lol If it makes you feel better, most breeders agree that it takes a few days for their nerves to develop to where they really feel pain. Many put them in the freezer where they go into hibernation and die. You could do that then feed them to the snakes if you have to. If you keep them, good luck with them!! Shame you're not here..I have a female that gave birth today, we could try to adopt them in.
