Hello,
I found this thread after searching for help for one of my pullets.  She hatched on April 3, 2018 so she is not molting as the original poster's hen, and not quite laying age yet.  My flock consists of 6 pullets, 2 Buff Orpingtons, 1 Black Australorp, and 3 Ameraucanas.  Of the 6, the Ameraucanas are the smallest but 1 is exceptionally small and feels like she is just skin and bones.  She is not growing/gaining as the other 5.  At first I thought she was just on the smaller side, being the 2nd smallest in the flock, but as time has passed, she is staying scarily thin.  The smallest in the flock has now surpassed her in weight and all of the pullets feel full an fluffy except the one in question (Olive).  I have seen her eat and drink.  Not sure about her poo though.  Any suggestions? I am new at this so any good advise from would be greatly appreciated. Thanks!