omg our broody decided to poop on her eggs but then she hatched three. And yes that poop i so smeelly.Hey don't give up! She has to eat and drink to live, yanno? Did she get back on the nest afterwards? it's normal for her to take breaks of 10-20minutes in my experience. Hens don't really have a lockdown, until they feel the eggs moving and chicks squirming underneath them.... that is when you cannot remove them from the nest, at all, lest you lose a finger.
You can put the food and water closer to her (I even put a food dish IN her nest and put lettuce all around her so she could sit & eat) but she will want to get up to poop not on her eggs once per day. That once per day poop is pretty smelly too.