What a heartbreaking story. I wish the shelter had been willing to give someone else a try to help Kona. Maybe a young single person could have spent the time she needed with her. Or maybe if you’d done a GoFundMe and got her a few more sessions with the dog therapist?
But I get that this situation became impossible for you. Given that there was no one else willing to help Kona, I understand your decision. I just wish that you had taken her to the vet to be euthanized rather than have the shelter do it. That way Kona would have been with someone she knew and trusted and loved in the last moments of her life.
I think this is an obligation we have to our pets. If they need to be put down, we need to do it. We need to be with them and offer them comfort in the last moments of their life.