Also, I'd strongly recommend moving her to a separate pen/coop/stall, screened off portion of the coop or whatever. Hens, even very broody ones, can be very dumb about getting back on the right nest. She may get off her nest to eat and drink, as is normal, but if there are other nests around, she may just as easily get on one of them and leave her eggs to chill. Also, other hens will lay in the same nest and this will result in eggs getting broken, pushed out of the nest, developing at different rates (if at all), in other words usually a complete loss. She may resent being moved and stop brooding, but if any of the stuff that I mentioned happens you'll definitely have a total loss. Most cases I've experienced, if she's truly broody you can move her to her new nest at night, maybe even put a basket over her for the first night and give her fake eggs to make sure she's broody, and then give her the eggs you want her to set. Fortunately hens can't count time and a few extra days of brooding won't bother her, after all you can hatch duck eggs under a broody hen and they take 4 weeks to hatch. In a pen by herself (with her own food and water) she won't have any other nest than her own to get back on. I've never had any real problem letting her back with the rest of the flock with her chicks... but of course you must make sure that the chicks have access to feed and water. Fortunately you don't have this problem with ducks; they seem to be smarter than chickens about getting back on the right nest. Which is good because a broody duck will usually not tolerate being relocated.