Well I had a suspicion very early on that one of the eggs wasn't developing and sense there had been no sign of progress from the last remaining egg I cracked the end open to see if there was an internal pip (into the air cell, which is how they get their first breath) , instead I found an egg that might have developed a few days but had then stopped. So I buried it next to the chick that died and removed the nest box from the cage.
With the removal of the nestingbox from the cage mom and her one chick are getting use to a little more space so baby can learn how to stick around mom for warmth and to learn how to follow her. They have a chick waterer to drink from and chick food will be here this afternoon. But the lack of food really isn't a problem for new chicks, they absorb the yoke which can feed them for 2 or 3 days until all the eggs are hatched and mom is ready to lead them to food. So far they are doing well and in a few days I'll let them out of the cage, but leave them shut in the coop with the other two cochin hens so that they can get use to the other birds and even more space. Then after that when the chick is a little sturdier and they have gotten the sticking together down I'll open the door to the run and let them be. I've added some smaller size wire to part of the fence that has bigger holes so that the chick can't get out into the yard where mom can't reach it. So hopefully this little one is a pullet (female) or I'm going to be heart broken in a few weeks.