Do a search on broody hens, there has been a LOT of discussion about them already. It's a lot of fun to have a hen hatch out chicks and care for them, and not too much work on your part.
She can stay where she is, but it's ideal to have her in her own private quarters. Even if you can just block off a corner of the coop for her, so other hens don't get in and so she can't get out. Other hens may push her off the nest and leave their own eggs there. Your broody may get confused on her way back from her daily coffee breaks and go set on a different nest, leaving her egglings to cool & die.
She'll just need enough space to get up and take a few steps to go eat, drink & leave her big smelly poop. If you have to move her, do it well after dark. If you can't separate her, at least mark the eggs under her so you can remove any new eggs daily.
Two big important questions: are your hens' eggs fertile? And do you have plans for extra roosters that might hatch?