I have a broody hen. She has been broody about a week. I put a fertile silkie egg under her, but I have an opportunity to either put some newly hatched chicks with her or possibly get some ameraucana eggs to put under her. I don't know if she will raise the chicks or hurt them. She has only been broody for a week. If I put eggs that will hatch soon under her will she be okay and raise the babies. I don't know if a hen can tell that it is or is not 21 days. It's getting late in the season and starting to get cold at night. Lots of things to consider. I am fairly new at raising chickens. Can you give me any advise?