She does look a bit yellowish. That sometimes may be a signal of liver problems. I agree that I would stop extras, and feed a balanced layer or flock raiser feed, perhaps with a small treat of cooked egg occasionally. Feeding a large amount of carbs could lead to fatty liver disease. Hens who have stopped laying due to molt and then take a break during winter shorter days, may become pale and the comb can become shrunken. Can you get any pictures of her droppings? Are her urates white (the white cap on the dropping?) Or are they yellowish? Does she have any swelling or enlargement of her lower belly under her vent?