I have a red sex link hen that is about 16 months old and has lost a lot of feathers on her back and tail. She has not laid an egg in a few months. Her comb has shrunk, and she seems weak. She spends the day away from the rest of the flock eating bird seed, and just being very quiet. She has an appetite, but I don't think she's getting all that she needs. I feed chick starter, oyster shell, oats, and just recently black oil sunflower seeds with the shell still on. She has also been getting cat food. She seems to prefer laying on the ground at night. I have also noticed the rooster chasing her as well as the pullets we added a few months ago. Is she molting? Nothing seems to scream illness to me, as her symptoms all seem external. She is growing new feathers. Should I separate her? I have a 10x10 dog kennel coop with a run attached. If she needs to be separated, I am thinking of making a small triangle shaped pen in one corner of the coop to keep her in. That way she will be secure, but still part of the flock vs separating her completely. Would this work?