Hi. I am so new to chicken raising and your wonderful site that I don't even know where to post my question. I have 6 - 22 week old chickens. 3 Rhode Island Reds and 3 Tetra Tints (or so I was told). My neighbor swears the Tetra Tints are White Leghorns. All grew normally until about 8 to 10 weeks old. One of the Tints/White Leghorns just stopped. She looks totally normal for a 8 - 10 week old bird. She is 1/3 the size of the other birds. Tiny little comb. No red on face. No feather missing. No mites. Seems to eat and drink normally. Only difference is that she does retire to the coop much earlier than the rest of the chickens. Other birds are either already laying or starting to lay. She is not. They have all eaten the same food and treats. We have no roosters. Any help would be appreciated.