My dove is dead. Presuming, delaying, mis-communicating

My dove is dead.
The hearbreaking part is that two days passed between first noticing her injured wing, and finally to taking her to the Vet.

I had tried to work out the problem myself. This is what I observed.
Nothing had broken in to my cage. They didn't seem nervous or worried, even when the neighbours cats came to 'keep them company' sitting under their cage. There were no pointy dangerous things in the cage. Except maybe the beak of the other bird
I worked out it was probably a 'lovers quarrel', with the under-bird (slightly disabled, very cute) finally pecking back at the dominant perfect one. Since the injury they had traded places, with the wonky bird now eating first, getting the good sitting spot.

The vet knew differently. She was in fact an attack by an intruder. Her wing was broken, she was in "excruciating"pain, and would never fly again.
The vet thought my distress was in loosing her, and kindly offered to let me hold her when we put her down, but that wasn't it.
Its the distress at how much damage lazy thinking can inflict.
"She'll be right" is what I thought of the small gap in the cage I designed.
Its what I thought about the cats lurking ("nice kitty")
Its what I thought about her recovery,without me having to bother with a vet visit.
Convenience thinking, cheap thinking. Awful results.
Doves are a prey animal, the vet explained, and the reason they look so relaxed with the cat around is that they are pretending. Predators choose the weakest of a flock, the one that looks the most nervous, so without claws or fangs, all they can do is act breezy, while their little hearts are beating like mad.

Saying goodbye, she looked perfect, not a reproach. Pretty black eyes, snowy-white feathers with a warm, wonderful smell.