I'm new to chickens, and have 8 week old hens that I am thoroughly enjoying, but my golden sex-link lies down much of the time. I've checked her vent for cleanliness, and that doesn't appear to be an issue. She seems to be growing at the same rate as the others and looks healthy to my untrained eye. She's eating and drinking as well, though she'll sometimes lie down to eat. She gets up and wanders around from time to time, though she walks only 3-5 feet before lying down again. Her personality seems to be very calm and even-tempered. Could this just be her personality or what else should I be looking for?