Sorry for your loss. It is good to try and get a necropsy through your state vet to find out what killed her. Some do their own necropsies at home, which can sometimes give a few clude as well. Here is a list of state poultry vets who can do a necropsy if the body is kept cool:
https://www.metzerfarms.com/PoultryLabs.cfm
https://www.metzerfarms.com/PoultryLabs.cfm
