grass clippings can make the droppings green and it doesn't sound like it's gapeworm. It may be as @Eggcessive suggested. Are you able to get her into a poultry vet?
is there rattling in the wheeze when she breathes? Also, is she extending her neck with her beak open? What do her droppings look like?
When was the last time she was wormed and what did you use?