Try giving her sulfadimethoxine. Dosage is 1/2 teaspoon per gallon of water for no more than 3 days. Use an eyedropper to put a couple of drops on her beak to drink. Do this 5-6 times a day until she can drink the mixture on her own.
Cocci oocysts are everywhere. In 2 week old chicks, I'd suspect their feces. Waterers or feeders could be contaminated by feces.
http://thecozynest.com/understanding_coccidiosis.htm
Give her milk until you can get corid. Use an eyedropper and put a drop or two on the side of her beak to drink. Do it 3-4 times tonight, hopefully the milk will slow the protozoa from making her worse.