I checked for eggs today and found this! It was not laid by my problematic Brahma- she was in a separate pen for the day. There were two brown egg layers present and one leghorn. There were two brown eggs in the nest and this. So I would assume it came from the Leghorn. They are still pullets so I guess all can be expected. So far (since 4.5 months) they have laid very beautiful eggs very regularly. One anomaly was a brown round egg and I found a perfect yolk on the ground. The Leghorn has laid two double yolk eggs. I'm not worried as I think it's just an egg that didn't go through the normal development process for some reason. Curious isn't it?