Can you get some Super B Complex vitamins? Human kind....1 pill, crushed and added to 1 gallon of water daily. Is the rickets a firm diagnosis or a guess from symptoms? I'm not a Vet, but this sounds to me as if the poor thing got an overdose of the D.
http://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
My advice is either call the Vet back and explain what is going on and have them give you some cortisol drugs to help clear it from the systom or you can wait it out. Either way it is going to take time for this to clear the body. No fortified treats or extra calcium in her diet. No layer mash, no oyster shell. No dark green vegetables either. You can see if she will eat small pieces of apple and please get a small bag of regular chicken feed, not one for layers, seriously, layer feed is making it worse if I am correct.
Another thing coming to mind....the Super B Complex has vitamin C in it as well as the Bs. Usually, this is a great way to treat signs of neurological issues such as stumbling gait, etc.. In this case, just get a B Complex and add to their water. Not as many Bs in it, but no C which could cause problems with too much D.