I have had very good luck raising chicks in the flock. (or I should say in letting a broody raise them). If you are unsure of your roo, or would like some different breeds, and have a broody now.... I would go and get some day old chicks, and slip under her at night, when she has been broody about 21 days. The thing is, if you wait for the roo, the broody might give up.
It is magical, the moment she feels them moving under her, her voice will change, she clucked till I thought she would be hoarse.
My hens do free range most days, and at hatching time, I do get down early and let them out, so all have enough space, but within 24 hours, the Broody will have them out of the coop, ususally staying close to the run for several days. But they are healthier, and stronger, because instead of being kept in a box standing in their own sh&* they are out catching bugs, crawling over sticks, up hills.
Please, please God, let me have a broody hen!
MrsK