I am very sorry for your loss. Is there anyone who could do a professional necrospy on her body? Many of us do home necropsies on chickens who die, just to see if there is something unusual that points to a cause of death. Taking pictures of organs (liver, intestines, other,) and looking for the pressence of yellow liquid coming out of the abdominal cavity, would be good. Liver disease, heart failure, and reproductive infection can cause ascites or yellow fluid inside the abdomen. If you are interested in a necropsy, keep the body cold, and here is a good video with the organs labeled: