E.Coli is present in their digestive tract, but if they get some other problem, such as a virus, the E.Coli can go all over the body infecting different organs. She may not have E.Coli, but it is very hard to cure if it is a systemic infection. Did she have a Mareks vaccine? Some of her symptoms of problems walking sound a bit like that, but it may not be. She needs grit for anything other than chicken feed unless she goes out on the ground and eats tiny rocks.