I have a RIR girl who is right around 12 months old. She hasn't layed an egg in a few weeks, and she just doesn't seem like herself. She does eat and drink normally, but she is the last one to come out in the morning. She is molting just a little, and a friend of mine, also a chicken owner said that most chickens around a year old stop laying for awhile because their bodies kind of go through like a resetting period. The only other thing I observed is that her comb is turning a more pale purplish color. I will try to take a picture of her tomorrow. Another thing to consider is that the weather here recently changed. It went from the high 70s to frost at night in just a week and a half... I live in northern Wisconsin and weather here is terrible. It seemed like she started acting different right when the weather changed, but maybe it's a coincidence. She has no runny nose or eyes, no signs of respiratory issues... No signs of lice or mites. Help please! She is a sweet hen and very much loved.