I know that not all chicks are created equal but I have 3 RIRs hatched the same day. Two are about equal in size, but one is half their size. She eats well and seems fairly energetic, but not as much as the other two. They do not gang up on her, in fact, strange as it seems, if she squawks a lot, like when I pick her up, the other two come running over. They seem concerned. At night, when they roost, they put the little one between them. Should I be worried about her slow growth? Does this mean she may not produce eggs? Could it be that she is not ingesting enough grit so is not getting the nutritional value from her food that the other two are getting?