I have a 12wk old speckled sussex pullet that stopped growing at about 6 wks of age. Literally. She even still has the downy feathers sticking out around her other feathers that were coming in on her head. The new feathers that were coming 6 wks ago are still the same length and even still in the sheaths. It's literally like she stopped aging. She even walks around and peeps constantly like a baby chick. I bought 4 differnet breeds at the same time, all day olds and she is 1/2 to 1/3 of the size as the rest. She's eating and drinking but doesn't scratch around the yard with the others. I'm beginning to question her quality of life. She's out in the coop full time now and I think she's struggling to stay warm where the others are doing fine. Any thoughts?