I finally cracked open the incubator eggs today. They were four or five days overdue for hatching, so I figured either they weren't developing or they were dead. I was right on both counts. Three didn't develop and three were developed chicks, but dead. I don't know why they didn't hatch.
And things aren't looking good for sitting hen. I checked her eggs today. They smell, but I don't know if it's because they had a rotten egg break on them and stink them up a few days ago or if they're rotten themselves. I guess I'll just have to wait and see what the hen does with them. She's still diligently sitting, but I feel so sorry for her. She's spending all this time alone and it looks like she'll have nothing to show for it.