Okay, then I guess vitamin therapy is about all you can do. It could be genetic but sounds more like that one is very vitamin deficient.
I'd also try giving Poultry Cell, like a couple of drops in an eye dropper, directly.
Do you know what spraddled legs are? Just curious if that's what's wrong as it may not be too late to bind her legs to fix it.
The B12 or a B-Complex is great to give in her/their water for issues like this too.