Is there hope for older hen laying "rubber" eggs?

[BigBlueHen53]

I first noticed this 4-yo EE had a dirty bottom about ten days ago. About the same time I started getting thin-shelled or shell-less eggs, almost aalways in the poop tray. I clipped her dirty feathers and bathed her, and started giving her a calcium citrus +D3 tablet every night just at roosting time. When I handled her I also noticed that her crop felt significantly fuller and harder than her flockmates', and I wondered if she had a crop or digestive issue as well, so I've also given her some frozen coconut oil. She doesn't appreciate any of it but is fairly easy to catch off the roost and docile in our hands - she just fights having me put things in her beak.

Treatment has been going on for about a week now, but I'm still getting the "rubber" eggs or shell-less ones. One day I found three rubber eggs. Today I found a wet spot, a yolk and whites only, no semblance of shell whatsoever. Another day I found only an empty leathery shell and a wet spot; I imagine somebody ate most of the contents.

I'm of the opinion that this old girl is at the end of her reproductive life, but I'm not knowledgeable enough to diagnose. Is this EYP? Cancer? Or something else? If she's not going to get better, - is it time to euthanize? A vet is not an option.

Thank you for any advice, suggestions or opinions.

 

[Blue is my chicken]

What I would do is see if she will go broody, if you don't want chicks then give her real eggs (the eggs that you get from the coop so that it is normal) and when she is broody switch them for fake eggs, this is the site I use (it is for ducks but it is the same principle)
https://www.tyrantfarms.com/why-and-how-to-make-a-duck-go-broody/
Good luck i hope your hen is okay
Edit: maybe someone more experienced will help