Coccidia produces mainly bloody stool not green and I'd be worried about throwing a medication at them they might not even need right now. The white parts in chicken droppings are urates which are basically concentrated urine-- so a total lack of them in droppings would indicate dehydration and/or kidney failure.
That being said, try offering treats with more liquid (cucumber, grapes etc) to provide a little extra hydration if some of them start looking dumpy. I'd hesitate to add electrolytes to the system because I'm not sure if (with kidney problems) they'd actually be metabolized well... but keep monitoring for sure. Isolate any birds that seem off, even if slightly.
The other girl had crop issues, and this girl had thrush right? Wonder if the other girl was also dealing with it... your vet didn't suggest any treatment for the others? Did your vet recommend anything?