We do have a vet but i am not sure about him providing with sulfa medications.Do you have veterinary care where they might give you sulfa antibiotics? Make sure that she is drinking well, and you might try some plain yogurt mixed with a little cooked egg. Buttermilk is also good if you have that. I would not recommend giving vinegar water to a chick with possible cocccidiosis. Keep her bedding dry and clean since the more coccidia organisms in her poop and the dirt she is exposed to can make her more sick.
Should I remove their waterer and change it with simple fresh water?