Another boxed chicken

Yang is quartered in the house again.  I brought her in yesterday when I saw her hunched up and not eating breakfast.  I don't know why, but she's underweight and seems listless, compared to her sibling Yin, so she's in rehabilitative care.She's into it.  She likes cuddling,and seems to eat pretty well, if timidly, on her own. I gave her a roomier box today, with a decent view of the room.  First she went to the very back and made herself a nest, but then she edged up to within extended-neck's reach of water and snacks and settled in there.   She goes back to the back if I make loud noises.I can't figure out if she's exceptionally meek, or if she's ill, because a chicken usually has much more energy than this.  Ie., they're usually ready to tear a box apart, upset their water dish, and let you know, very loudly, that they do not thrive in captivity.  But for now, she's been admitted to the box and the all-you-can-eat buffet for observation.