What does your dog crate look like? How big is it? and how any chicks.
I manage to keep my bantam momma hen and her three little ones in a guinea pig cage for about two weeks. For the first few weeks, the little ones stay very close to momma.
Then moved them to my aquarium, which is bigger, but on the back porch where it is colder. She was there for about another week or so. Then it warmed up enough for me to let her out and free range with the rest of the gang. I put her back in the aquarium at night though, to keep her and the chicks safe from vermin and warmer.
Hope this helps some.