My chickens take turns setting on eggs?

[chicksavy4]

I had a broody hen and I let her have 7 eggs. I marked them so I could collect the fresh ones. I went out to the coop a couple days or so ago and a different hen was sitting on them! Two days later another different hen took over. There is constantly a hen sitting on the eggs but a few different hens have been doing the job. Should I still try to hatch the chicks? Or throw the eggs out?

 

[GitaBooks]

This is a common problem with broody hens, one I've faced multiple times.
When a broody decides to use a communal nest, the other hens take the fact she is using a nest box to mean that it is the best and all want to use it. They will chase her off or even just sit on her, laying their eggs and than leaving (sometimes another broody may try to steal the nest). This leads to eggs that will all hatch at different times, broken eggs, and eggs that go cold, as well as a stressed broody.
I would suggest collecting the marked eggs and trying to move the hen to her own broody pen, one where other hens can't get to her. You could try blocking up the nest box with wire during the day, so others can't get in, but letting her out to feed each morning. The only reason this won't work is trapped hens will step on their eggs while trying to get out.

If the marked eggs have gone cold, I would suggest starting over with new ones. A dedicated broody should wait the extra days for them to hatch.

I hope everything works out well. Best of luck!