The process was to see which hen wanted to hog the eggs, mark a few and collect the rest. Left the marked eggs in the same nest and all the hens wanted to lay in that nest so i let them. Neat thing was the eggs never got left with no warm butt on them but it wasnt always the brood mom so in 21 days i had chicks, no fuss no bother. When all the chicks were hatched i moved the mom with the chicks into a brood pen made of hardware cloth inside the coop where the hens could see and smell them and hung feeder and water low enough the chicks could eat and fed them and mom medicated crumbles. I kept the mom in there for quite a while. She didnt have a choice and she cared for them til I let them out and protected them even after that.
While she sat on tne eggs she was free to come and go as she pleased which she did. When she left, another hen would jump right up and keep the eggs warm while she laid then she would hop off the nest and mom would come back. At one point i had 2 hens fighting over who was mom but the real mom was pretty obvious so i encouraged it. Point is, if she is really a mom she wont hurt the chicks so you can keep her with them til you think they are big enough to be let out and, if she really is a mom, she will protect them in the flock.
This particular mom was always a mom, she didnt go broody. She would always try to sit on the eggs and if i marked some and left them she would stay on them. I guess thats why this broody business was new to me :-)
The only 2 i lost was due to sharp corners in the coop. I now have chamfered corners (diagonal 12" plywood across the corner) so the chicks cant be trapped and pecked to death. My coop is much safer now for the chicks.