re... feathers everywhere

Hens go off lay when they are moulting so their food intake does dip.

I would stop the mealworms and other treats for now and make sure she is eating plently of layers pellets or mash.  Feathers are mainly protein based so many chicken keepers feed tuna (in water not brine) or cat food during the moult.  Mealworms have a lot of fat and should only be an occasional treat 

Moulting can seem a bit drastic first time you have to deal with it, but if your birds are fit and well, they will bounce through it with no problem