My FIL had a silkie hatch 3 standard brown leghorns and brought them up to me to care for. I've had them in the house for the last 2 weeks and decided to take them out to the coop tonight and put them in "chickville". I checked a few hours later and it was getting so cold, even with the light over chickville, that they were becoming lethargic. I had to bring them back in. Anyway, I have a silkie out in the coop with two 4-6 week old chicks that are fairly large. They are also brown leghorns. I noticed tonight that she roosts with them underneath her. What I'm thinking is, if I were to put her back in the cage with her favorite nesting box and slip those babies in at night, do you think she would accept and care for them and keep them warm? I can't have chickens in here all winther!