Scratch is supposed to be a treat, for once or twice a week, a pinch per bird. It's not good for them.I usually mix them about 50/50.
They're both the beaver brand crumble and 6-grain scratch.
They also have a vitamin supplement I put into their water.
Standard 16% layer is the bare minimum of nutrition a bird can eat and still lay and survive, watering it down with non nutritional scratch further takes away nutrition.
She's likely malnourished, a chicken will eat until their nutritional needs are fulfilled and since it's not, she's gorging her self and not getting anything .
Cut out the scratch completely and get a higher quality feed that's atleast 18% protein