I have a welsummer about 6/7 months old who is still nothing but skin and feathers. She roams the yard the other girls and I see her eating and drinking normally. She isn't being picked on either. Just tiny! I've added some nutrients to the water the last few weeks but it doesn't seem to be helping. The girls have access to multiple feeders with laying pellets and also have a large fenced in area to roam during day. Doesn't have any signs of being sick. Is there anything I can do to help her put on some weight ?