Here's a link to lash eggs. In the article you will see a response from a vet. Assuming the vet knows what he is talking about, there might have been hope for your hen. Don't be too hard on yourself for grasping at straws trying to save a favorite hen.
http://www.theartofdoingstuff.com/the-lash-egg-or-what-the-hell-just-came-out-of-my-chicken/
This thing was huge. I've been massaging her abdomen daily, to see if I could move it along, but it was way too big to move by the time I figured out she had a problem.
Perhaps her gizzard was the original issue, or maybe even her stomach.. She was really thin by the end of it all. She wasn't eating mash or crumble, but she was eating greens and scrambled eggs.