Mary will be cremated by the Animal Welfare League (I know you have good reasons for not liking them Lozzy, but I don't have access to providers with services as good and as affordable as theirs).
In addition to simple cremations, they also offer mementoes containing a few ashes. I'm going to...
The only thing I know about surgery is that it's not always an option. It depends on the hen's anatomy and that can only be determined on the table.
If you have a vet willing to give ot a go, do it.
@ManueB has more experience than I do. The cost was rather prohibitive where I live, so there I've only tried it once. It worked as expected, that is, the effect lasted for a few months.
She jogged a couple of weeks ago (after her first round of antibiotics) which gave me great hope, but she slipped back into her decline.
The second round of antibiotics gave her a couple of good days. But she was suffering since Wednesday and it was only right that we helped her along at her...