I'm new at this too. I've been reading everything I can get my hands on trying to decide how to handle my BO and her chicks . once they hatch. There seem to be two distinct schools of thought on the issue.
1. Protect the babies at all costs. Isolate the hen and her eggs to keep them safe from the rest of the flock.
The downside of this is (as I see it), hens are quite social creatures, and isolating them would be like putting a pregnant woman in isolation for the duration of her pregnancy and the infancy of the child -- and we all know that wouldn't be wise.
2. Hens have been hatching eggs in the company of the flock for thousands of years. leave her alone and provide food and water through the incubation then let her deal with the other hens and her babies.
The downside of this one is that a chick might get hurt by the adults in the coop, or the broody may not turn out to be a very good mother allowing the chicks to die or be killed.
I don't think there is any set answer.
I'm doing the "wait and see" thing. Marlena, my broody BO, has 5 eggs. One is peeping this morning and she changed her schedule dramatically. Usually she comes out for her constitutional mid afternoon, but this morning, she was out before the run was open at 6 a.m. I checked the eggs while she was out, and all seems to be going on schedule (today is day 19). My plan is to watch and see what happens with the chicks. If she is protective and taking care of them they will stay with the flock. If she isn't as protective as she should be, she and the chicks will be moved to my portable coop/run for a few weeks with time to free range with the whole flock every day. If she is careless, I'll bring any babies she has in to my brooder and raise them myself. The whole point of this exercise was to let her raise some chicks, so .....
I am not an expert, but I have read a great deal about broodies and hatching. We will see how that translates to success.