I would make her a pen inside the coop. Big enough for her nest, food, water and a place to get away and poop- if your coop is big enough to accommodate one. If it isn't (which mine isn't), here is what I do. I have a large bird cage, there is no food or water inside, just the hen and her nest. Everyday I open the cage and remove the hen from the nest so she can eat, drink and poop. Then I put her back in, close the door and repeat the next day around the same time. Leave the hen on the nest for the last 3 days. I also use an XL dog crate as a broody pen outside the coop. It has hardware cloth on it so no predators can reach in and one end is wrapped in a shower curtain I picked up at the Dollar Store so they can stay dry. If the other ladies can't get to your broody, they can't eat her eggs. Good luck!