Her droppings look a lot like those I have seen of pictures of coccidiosis. I would get some Corid powder and treat her with 2 tsp per gallon of water for 5 days. But you can still get a fecal float done to confirm it. Another problem with chickens and yellow green or yellow stools is E.coli infection. That requires antibiotics, probably from a vet. Let us know how she does.
