When I have a hen that insists on setting where others have access to their nest, I draw a circle around her eggs with a Sharpie. I don’t take the hen completely off the nest to check for extras. I just slide my hand under her, lift her enough to give the eggs a quick glance, remove what I need to and put her back down. As for your current situation, there is no harm in giving it another few days. If something hatched, great and if not, just dispose of the eggs.I'm not sure how I can manage it, if the other birds are squeezing into the box to lay in there. They have all laid in different places in the coop.
For now, I assume I can just take the bird off the nest and take all the eggs. With no eggs, I'm assuming she'll quit setting quickly. But the next time, I'm going to have the same issue with other eggs. The box is up off the floor, so I don't think she can get eggs up into the box. The other hens have to be laying in the box with her there, and she is collecting them.
I guess I could take a magic marker and mark the eggs she is setting on at the beginning, then take her off the nest every night and take all the unmarked eggs. Would that work?
And how long does an egg have to get to brooding temperature before it starts developing?
If there's a better plan, please let me know.