Agree with Ridgerunner. All mine were raised in with the flock, and I will not separate future clutches unless they give me reason to. Some set their eggs there, too, although that did require moving the broody onto the correct pile of eggs several times (often as not, I would find another hen keeping them warm.) Worked out pretty well, really, but I am home to check on the chickens several times a day if needed.
I would not put a broody in something like a cat carrier, as I often read of people doing. I feel they need to walk about more than that every day. During their break, I see them go outside, dust bathe, scratch and peck, as well as hit a feeder and waterer. I have a 5x6 pen inside the coop, and a usually unused coop that's maybe 4x8, so there's room for a broody to set the eggs.