I'm sorry to hear about Hennifer
Hard to know what's happening with her, but I would suspect some type of reproductive issue. Fatty Liver disease also comes to mind.
If she's had troubles with production, then you can try getting extra calcium into her to see if she's able to expel any material (Lash, membrane, etc.).
A crop that is not emptying is a symptom and usually goes hand-in-hand with reproductive disorders, infection, etc.
If you happen to lose her, then having a necropsy through your state lab will give you the best answers as to what has caused the decline. Some of us do our own informal investigations and sometimes we are able to find some clues.
https://www.metzerfarms.com/poultry-labs.html