Can each hen cover all the other’s eggs? Seramas are pretty small. If the eggs have been covered no damage has occurred. If the Serama could not cover all the other eggs, there is some risk but you may still be OK.
I’d put each hen back on the right nest. Sometimes broody hens get confused as to which nest is theirs, especially if another hen is laying on egg in their nest when they get back from their daily constitutional. That’s happened to me a few times. One time a hen had been off her eggs for most of the day based on how cold the eggs felt. I put her back on her eggs and she still hatched 11 out of 11 eggs. It’s not a good thing to happen but it’s usually not the end of the world.
I usually let my hens hatch with the flock but you may need to do some isolating for one of the hens. You could fix an isolation spot, essentially a cage the hen cannot get out of and no other chicken can get in. Lock her in there with a nest, food, and water. The risk in moving a hen is that she may break from being broody. I have moved a few, stuff is always happening, you have to stay flexible. I find if I move them at night and make the new nest fairly dark they take the move pretty well most of the time. I make that nest so I can lock her in it and leave her locked in the nest pretty much all the next day.
If you can manage it, another way would be to build a cage around one of those nests and lock the hen in that nest, with a bit of room for food and water. That way you are not moving her.
Good luck!
