...I was glad that I delayed doing anything with those eggs; the next day a white hen was setting the nest and my original setter was off in the pen teaching her two chicks how to hunt for bugs.  I thought it odd, but interesting.  But it got even more odd; that evening the original setter, now new mama, returned to the nest and ran off the white hen who protested loudly all the way to the hoop house.  Even odder is that the next day the white hen was back on the nest and the original setter was again in the pen teaching her chicks to hunt bugs.  Once again as evening approached, the white hen was sent off to the hoop house.  This continued for several days.  Then when I began to accept this behavior as "normal" for my farm, I saw on the evening of the second day the two hens sharing the nest.

Since my farm is not normal, the sharing only lasted till the morning.  The original setter, now new mama, was gone and so were her chicks.  I didn't know where she was or even if she and the chicks were OK.  Thankfully, two days later she showed up with her chicks, hunting for bugs around the chicken house and pen, but she has not entered the pen where the white hen is still setting.  I am not sure if the eggs will hatch with all this "normal" behavior going on.