I have two 12-week old Pekin ducks I got from our local swap meet. My male, Finn, has always thrived and done well. My female, Remi, has seem to always have problems. When she was a few weeks old i started her on Niacin capsules because her legs started to cross. I seen improvement pretty fast. She's always been on the smaller side compared to Finn. About a week ago i found Remi unable to walk. She would move around using her beak and wings, its really sad to watch. Two days ago I realized i got flush-free niacin and i was so mad at myself. I then proceeded to buy vitamin B12 and shes been on it a couple days not with little improvement. It doesnt seem to hurt her and she isnt fazed by me touching her legs but idk what caused it or what to do? Last resort ill take her to a vet but i dont want to if I dont HAVE to. I even had her right leg splinted for a while but she wont walk on it. If it is a niacin problem is it too late for her?