Your poor baby

I hope you can get her a vet asap. I had a budgie lose a toe to a lovebird and had the same situation, no vets open to see her. But I was able to look after it myself and luckily it was just a toe. Her whole foot is another story.
Put her in an aquarium cleaned and sterilized with a heating pad underneath half of it (she needs to be able to get away from the heat if she wants) and clean the leg. I used polysporin right on it and cornstarch to clot the blood. Keep an eye on her and make sure she isn't licking it to injest the polysporin.
My budgie made it through her toe loss, but again I don't know how well this will work for your bird. Please see an avian vet as soon as possible. If anyone else knows better (if to not use any antibiotics) please let the OP know.