The subsequent photos don't depict the chick as truncated. Goes to show how deceiving photos can be. Also, showing her standing beside a cup, as long as it's not a children's tea set, she looks more normal size.
At this age, constipation can be an issue. It won't hurt to give her some coconut oil, a teaspoon. What I suggest is to hard boil an egg, and mix the oil into the yolk. She must have at least a teaspoon so be sure she eats it all.
Another cause of her lethargy could be the heat. All chickens do not experience heat equally. If she's having heat stress, she should be given electrolytes with a little added sugar to perk her up.
At this age, constipation can be an issue. It won't hurt to give her some coconut oil, a teaspoon. What I suggest is to hard boil an egg, and mix the oil into the yolk. She must have at least a teaspoon so be sure she eats it all.
Another cause of her lethargy could be the heat. All chickens do not experience heat equally. If she's having heat stress, she should be given electrolytes with a little added sugar to perk her up.