"Sleepy" chicken. Idk what's wrong with her :(

[nicolearbaiza]

My chicken (Elizabeth) just recently stopped laying and has been very lethargic recently. I've checked her vent, she isn't egg bound. I've checked her crop, it's empty. It was empty last night and still this morning so I'm assuming she's not eating all too much.

Can anyone help? Her sister (Annabelle) is also acting kind of sleepy, but her stool looks fine. I'm attaching some photos of Elizabeth and her droppings.

 

[chickens really]

What all do you feed..???..Treats/snacks included...