I have one older chick and had two younger ones. One of the younger chicks recently died. We moved the coop to a more sheltered area, thoroughly washed it, and cleaned out their water and food. The remaining younger chick is droopy, her eyes half closed, and when I let her out of the coop to eat grass, she never moves, only pecks at the grass and then sleeps, and then pecks again. Her wings dip slightly. I have tried adding a little bit of sugar in their water to perk her up, but after a few days she still looks depressed. How can I help her get better?