Here's what I do:
Broody chickens get their own crate with their eggs -
Once a day I have a small area I can let them out to poop, stretch their legs and wings, eat, drink, bathe- and then they go back to the eggs.
My flock is too big for leaving a broody hen to try and defend her nest and reliably tend to HER eggs- then the other problem comes when I have to wrestle the eggs out from under her every day to make sure there aren't any fresh eggs I don't want to develop ... so mine don't stay with the flock that way anymore.
So if it was me, the hen that broke the egg and ate it would be back with the flock and I wouldn't bother doing anything else with her (unless she keeps gobbling eggs).
I keep my broody hens in their crate in the house while they hatch - for at least 2-3 days. Chicks go through their "pollyanna" stage where they have not a clue in the world that anything might try to grab them up and eat them, whether it's another hen or a person or a predator.
Some purists will say "don't let her move after day 18" ... but once you've cleaned a poop-explosion - which is not normal poop- it is the stinkiest, most disgusting smell you can dream of - off eggs that are due to hatch, any hatched babies, the straw, and the hen's fanny - you may choose to do what I do.
Some of it comes down to that individual hen and how she deals with being picked up for poop time. Because I've handled this hen throughout her brooding time in keeping her separate, I have a good idea of her behavior.
For a calm hen that will carefully walk back into the crate and settle back on the eggs, I just lift her off and take her outside to do her business.
If she insists on being a maniac about re-entering the nest, (kicking straw around etc) I simply move the eggs to a straw filled container when she's removed while she does what she needs to - then I add those eggs back underneath her when she's calm and settled in.
When I hear that first magic "PEEP!!!!!" from inside the egg, I make sure that hen has a chance at a bathroom break. I've got a special spot on a railing they go once we're into time with peeping eggs and chicks.
Even if she has been calm up to that point, I make sure any pipped eggs are removed before she goes back in, post-poop. The reason for this is a pipped egg is now much more vulnerable to an accidental smash by being stepped on. They are immediately returned as soon as she sits.
Remember, once the babies hatch, they'll be squirming around her underside - which can be just enough to trigger a poop-zilla-explosion. They'll try and try not to poop but some just won't be able to hold it.
Now, if the hen has been relieved at the first chick pip/peep, MOST can make it the 2 days from the time of the first peeeeeping egg to the time when the chicks make their debut, especially if you keep the food away.
Even if all the eggs haven't yet hatched at the end of day 2 (counted from the first peep), she goes out to the rail for some "relief".
Now- behavior once there's an actual chick involved can change. I keep a 2nd very small crate handy, filled with straw. All pipped eggs and hatched chicks go to the 2nd crate when momma goes for her quick-poop-expel moment.
Why? She will be somewhat anxious to get back to them and may accidentally step on them in her overzealous quest to make everything "OK". Now- this is a matter of personal choice- it's your chicken, your choice. I simply speak from experience:
If you leave her and take the chance that she can hold it longer than those 2 days - if she DOES poop in the crate - you will have to remove her for a much longer period of time to clean her up. Usually when this happens, the hen's butt and underbelly get nice and saucy - and the only way to get rid of the wretched smell is by washing her off. And then she has to be DRY before she goes back so babies don't get wet.
Washing her off and drying her off and cleaning the crate, picking out disgusting broody poo in the straw, and making sure each chick is clean and didn't dredge themselves in the poop while momma was getting cleaned- all takes a LOT longer than a quick lift off to go poop. This will be a lot longer for the chicks to wait for momma to get washed and then dried off. Just saying. The other bonus is you can examine each chick to make sure no pasty butt or other issues show up every day.
After everyone has hatched, I leave the group in for at least a full day- unless momma gets up and starts kicking bedding around- at that point you gotta get her out somewhere bigger before the babies get caught in her jetwash. I'm set up with a "room" at the front of the coop where I can safely leave momma and chicks separate from the flock but where they can see eachother.
I prefer to wait until the chicks have some pretty good getaway sticks and are aware of threats around them. This gives momma a good chance to bond with them and figure out how to move with a gaggle of babies before she has to navigate the flock.
Average time in the separated area is 5-7 days after the chicks hatch. Generally I let momma hen out first with the flock to see how things go. If she's going to fight (and there's almost certainly going to be a fight at some point) it's better to not have a bunch of chicks trying to cling to mom, getting in the way (and being in danger). By that age they've started to have more awareness, so other hens are less of a threat- because they won't just sit there while a hen attacks.
Sometimes she needs to take a good run and flap before coming back for the kids. It all depends! The main things to watch for are a hen that won't leave them alone - or a momma that wants to fight over every last thing. As with anything, only they can work it out between themselves, but if something obnoxious is going on, it's important to remove the main perpetrator.
) and they have destroyed my garden space. I HATE pinning them up in a run, but I fear more trouble will come if I don't. I am planning on making a chicken wire covered area for the perimeter of the garden to their run, so they have more running space.
