I know, theoretically, that you can go to a lot of trouble trying to turn a hen into a brood mom and hatch eggs but i still believe you guys are way overthinking this.
First just let them sit where they want and the brood mom, if there is one, will show up. She will be the one sitting when everyone else is running around and if you leave the eggs you will notice one nest seems to be filling up and one or 2 hens always seem to be fighting over who gets to sit on them. About that time you mark a few eggs, collect the rest and see if they keep sitting. I didnt protect the brood nest from other hens, i let them all sit on the eggs if they wanted to. Eggs dont care who sits on them, they just need to be kept warm. At that point note the calendar, keep collecting unmarked eggs and see if any chicks show up in 21 days. If so you have a good rooster and at least one good brood mom. Now you can separate the broood mom and chicks into a brood pen large enough for her to take care of them and have their own feeders. i keep the pen in with the flock so the chicks become part of the flock.
If not then either the mom didnt stay on them enough or the rooster had a vasectomy when no one was looking because he didnt want to pay child support.
Thats how i did it, had a lot of fun, got some chicks and didnt kill myself with worry in the process.
I believe that's true in some aspects, and sounds very much like what the poster did, other than not getting chicks at the end.. that's what she's asking help for ?
Sometimes, a hen can't just be left in a main coop when broody, for several reasons..what if she's at the bottom of the pecking order..that could lead to another hen killing her chicks at hatch, or even ruining the hatch before they have a chance. Or other hens could like that nest the best, and eggs could be broken, rolled out of the nest, who knows...
Imo (which may not be worth 2 cents) there's not really any certain way it has to be done, just whatever works best for you and you birds. Doesn't mean that someone is doing it wrong if they don't chose your way, just means they are doing it differently. Both methods should results in chicks. . However, in this case, despite doing what sounds like a perfect setting by Kendell's girl, she didn't get chicks. .that's what she asking for advice on ..
Hope I didn't hurt anyone feelings, not trying to be rude...just wanted to let her know whatever happended5, wasn't her fault, she's not to blame.. and I honestly believe her method should have in all reality had her a nice group of fuzzy butts, but for whatever reason didnt..
Kendall, it kinda sounds like a humidity issue..which I've never seen under a hen?? Has it been really rainy where u are? I'm not really sure what advice to offer at this point, but I would take the earlier advice, and do an eggtopsy on one (after a float test to ease your mind on whether it is alive or not) and post the results here.. what feeds do they get? I doubt that had that type of affect on that many eggs tho, and if there was growth and movement earlier, your boy is doing his job..
So guess all that to say, I'm at a loss as to why it happened. . Honestly sounds like a textbook setting