Mine are much older at 8 weeks. It is remarkable how a broody will look after her babies. Now the small chicks don't seem to hang around mom but they know she is always in sight. They will do just fine. Just watch and enjoy it is a great experience. I have noticed the young ones don't think much of the snow. They come out, look around and go back in the coop. The 40 week chickens are not bothered at all.