No. All hamsters need to stay with their mothers until 4-6 weeks old. They are currently only 3 weeks old, and just weaning. But just because they are on solid food does not mean they are ready to go. They need to stay with their mother until they have reached sexual maturity. Food is not all she provides them with, they also learn vital social behaviours which they need to survive.
Bread dipped in low fat milk is NOT a good idea. Rodents cannot digest the lactose in cow milk. If you were to supplement their diet, it would have to be with goat milk or kitten formula replacement.
You cant seperate them! YOU HAVE TO SEPERATE THEM! Unless you want the babies in the mothers tummy! The mom eats their babies because they feel like there is so much bad things that could happen to them they feel like the only safe place is a stomach!