I know you are especially hurt and saddened by the thought that Flora was in severe pain and terror as she died. It took me a while to look up a few passages that I hope will bring you a little peace. It's something I took to heart years ago when a mink killed three of my chickens and a duck.
In explorer and medical missionary David Livingstone's 1857 biography, he wrote of being viciously attacked by a lion that "shook me as a terrier dog does a rat." Livingstone sustained a compound bone fracture, blood loss from 11 lacerations and subsequent infection.
Livingstone said the sudden attack produced "a shock similar to that which seems to be felt by a mouse after the first shake of the cat." There was, he wrote, "no sense of pain or feeling of terror ... this peculiar state is probably produced by all animals killed by carnivora." Livingstone called it a "merciful provision" for "lessening the pain of death."
I sincerely hope he was -- and some modern researchers are -- right, that animals as well as people are allowed to experience a stress-related, biochemical altered state that protects them from unimaginable fear and pain. I hope Flora felt that protection.