I have always let broody hens get on with the job. They sat and hatched in my house, in their coops, in other tribes coops, in the maternity units I built and occasionally in the wild.
I have limited the number of eggs in their clutch and I have moved them from in the wild nests to maternity units when I thought the nest sites were unsafe.
I mark the eggs and remove any donations from other hens usually. I've had double and triple sits; not usually an overall success because some viable eggs have been left in the mums eagerness to get the chicks out and mobile.
I don't confine them: they need to get off the nest and out for excercise, eat, drink and dust bath and I do provide food when they get off the nest to make sure they eat properly.
The getting off the nest and out and about is the one thing that needs keeping an eye on, some do it automatically, some need to be lifted out until they get the idea.
I try to keep the sitting and hatching to the more senior hens. Usually each tribe has an established senior broody hen and these are the hens one wants to sit and hatch if possible. There are far fewer problems, particulalry where integration into the tribe is concerned.
I will I hope, never use an incubator, but there again I don't care if they hatch less than the number of fertile eggs they originally sat on.
Of course, one needs a rooster and hens that go broody to make a proper job of it and I've been fortunate in ahving plenty of both and the space to let them do what they do best.