I'm kind of wondering the same thing. Out of 15 eggs, we got our little fuzzy Scout and that's it. Agatha has done a stupendous job taking care of him and he's thriving. But Agatha is showing definite signs of being OVER being stuck in the broody pen. Yesterday I close the coop off from the run after all the girls had laid their eggs for the day and opened her side door. She came running out into the coop and Scout was right behind her, exploring and finding tidbits of yummies when Mom scratched them up for him. If I so much as opened the coop door to check on them she puffed up and growled and he scurried under her. But it was only the two of them in coop then.
I do have the other 9 chickens to worry about. Scout is now 5 days old. Is it safe to open the doors and see what happens? - (remembering, of course, that Scout seems to have a death wish.) The other girls mingle around the broody pen all day long and she fluffs up, spreads her wings and growls if she thinks they're getting too close. They've seen Scout and he's seen them, and Agatha was still holding her own before he hatched when she'd leave the nest to be out with the general population for a bit. I hate to sound cold and callous, but if I had 15 chicks to think about I might not be as concerned, but since he's it, and he's Katie's, I am still hesitating.