If a bird isn't eating well then upping the protein a little can help get their nutrition in, or come from a food that they like and encourage them to eat. If she can eat her own feed, then you don't need to worry about that. If not, cooked or scrambled egg, canned tuna, even canned cat food...
Wry neck is fairly common and usually a vitamin deficiency. Treatment is vitamin E with a bit of selenium to help with the uptake of the E. They may need a higher dose of E to get it reversed, so using a straight E capsule, just poke it with a needle and squeeze it into her beak, is best. I...