This is what worked for me.
My coop has three sections. One section for the "adults" or laying hens, one section for the youngsters, and a section usually for feed and other supplies. All the sections can be kept closed off or I can leave everything open and the birds have access to all of it. The adult section has a covered run and the youngster section has a covered run. This arrangement does make for a messy supply section when the birds have access to it.
Right now all the birds have access to the whole coop and both runs. I turn the hens loose at about noon and the other birds depending on how easy it is to keep the hens in.
When a hen went broody I moved her and a nest box to the supply room and kept the other birds out of it. About a week or two after the hatch I would allow her and the chicks access to the adult section and to the outside world.
Momma hens protected their young and there weren't any real problems. The chicks stayed with the moms until about 4 weeks old and then they started venturing off on their own. At about 6 weeks the process was pretty much done. Integration this way was really pretty smooth. The moms are all different. I had one that taught her chicks how to get on the roost. The other two didn't do anything except leave the kids when the kids got bigger.
When the cockerels start going through puberty things start to get interesting. They aren't chicks anymore. That's when you have to start thinking about what to do with them if they haven't taken up residence in the freezer by then.