Return From Egg Laying Hiatus and Prolapse

Hello you wonderful community! Really calling for help on this one.

We inherited 10 chickens from our neighbors, the girls moved in about a month ago now. This is our first experience with chickens. I ADORE them! All has been fairly easy and going well until...

White Wing is about 6(ish) years old we are told, she previously hadn't been laying for about a year. Last week I noticed a walnut sized red bulge from her backside. I've done a bit of reading and preparing before we got the girls so I knew it was likely a prolapse. We separated her into a dog crate. Then we gave her a warm epsom salt bath, lubed up some PrepH and tried to reinsert the prolapse. This is then when i noticed she was actually trying to pass and egg, but it was way soft. She did end up passing it. The shell seemed to have cracked on its way out though which I know is not a good sign and the shell felt like a balloon. I've been giving her some extra oyster shells to hopefully harden the eggs and feeding her scrambled eggs.

We are now at day 5 of this journey. We've tried to treat her 3 times now. We tried to do another treatment this morning but noticed she was trying to pass an egg again. We left her in the epsom salt bath for about 20 minutes, she was straining and seemed to be in pain. Heartbreaking.

We called a few vets, but it's looking like that may cost $200+, and we just can't swing that right now. So what in the heck do we do?! Do we just keep trying treatments? Is this even possible for her to recover from? Do we need to cull her? Is this just initiation into backyard farm life?! Will my heart break in half if we do have to cull her?

I knew getting chickens wouldn't be glamorous, I'm not a glamorous girl anyways. But damn, didn't think it would be so hard so soon. Thank you in advance for advice/wisdom/compassion!