I was going to say mareks also, but the bird started losing weight BEFORE she became wobbly. Seabrights do tend to get mareks more than other breeds (in my humble experience anyway).
I would also caution against tube feeding without the help of an experienced person. If you get the tube down into her lungs, she's toast. If she is still eating, why tube feed? It's got to be some sort of malabsorbtion.
I would also caution against tube feeding without the help of an experienced person. If you get the tube down into her lungs, she's toast. If she is still eating, why tube feed? It's got to be some sort of malabsorbtion.