Corid is not hard on them. But I would worm her first. She may just have worms, but coccidiosis is also possible as sick as she seems, so I would start the Corid if you have some. Either condition can really harm her. At her age worms may more likely be the culprit, but I would treat for...
Welcome to BYC. She possibly could be suffering from worms or coccidiosis, but a reproductive issue such as egg yolk peritonitis or internal laying may also be her problem since she is not laying eggs anymore. Corid (amprollium) is the treatment for coccidiosis which is more common in young...