Update!! Bob ferociously gobbled down the egg and yogurt mash I made her!! She held her head up by herself when we kept our hand on her bottom to steady her. Hopefully she will begin to regain some strength!
That's good. PipsandPeeps might be on to something with the mention of wry neck. It is usually caused by genetics, toxins, or nutritional deficiency. You said this is new behavior, so it likely isn't genetic. The bird could have eaten something moldy and got sick. VetRx just helps with respiratory problems by relieving some symptoms. It may be a fairly good preventative but it doesn't cure anything. Chickens don't like it for the same reason kids don't like cough syrup. It has camphor in it and doesn't taste too good. I use it on a soaked q-tip and gently rub on the roof of the bird's mouth near the back of the throat. I put a few drops in the drinking water every so often during the Winter too. Those scrambled eggs are good nutrition. So is the yogurt. There's a way to get vitamins and amino acids in there quick with a product called Nutri-Drench labeled for poultry. That is if the bird doesn't drink from a waterer on its own. I hope your bird continues to get better.