Some people separate them, some leave them where they are. Broody hens will hatch eggs, some are better at it than others. Some eggs won't hatch. Don't rush her! The proverbial advice is to leave her 5 day (longest 5 days ever!) to make sure she will set. Truthfully, I have never made it 5 days, and often have had to start over, when she is REALLY sure. Once she gets settled, sometimes a little curtain, just part way down will help.
Mark your eggs that you want to hatch with a marker, not a pencil (it wears off). Check the nest every two or three days, by pulling her off with a towel over her head so she does not peck you. This allows you to check that no other bird has laid in there, and will keep the clutch a good hatch-able size. Pull out any unmarked eggs.
She will barely be able to walk, then stretch and go out and do her constitutional, terrorize the other birds in the flock and then resettle. If you are there, you can make sure it is the right box. Then she should stay there for another day (kind of, sort of).
Best is you need to check at least twice a day, and three times a day is best to make sure she is on the right nest. That way, you can just move her. Once I had one sit perfectly for 2 weeks, and came home and she was on the wrong nest, the eggs were cool to the touch, it was cold out. Advice on here, was move her back on top of them and they hatched right on schedule. I think it is a bit more crucial in the first couple of days, but once the chick starts growing, then they make a bit of heat themselves.
Again, not as good as an incubator, but if you are just playing around, it is fun to let her do them. If you are serious, and you have a little incubator, you can put some eggs in there at the same time, covering your bets so to speak, and when they hatch, set them under her with any chicks she hatched. Chickens can't really count.
Mrs K
