We never think they will get so intertwined in our hearts, but they burrow in deep and shatters our hearts when they pass.
It still takes me a long time to let go and I've lost many over the years. The heart will harden off, but you will never forget them. 
We never think they will get so intertwined in our hearts, but they burrow in deep and shatters our hearts when they pass.
Thank you. My aunt (chicken tenders and retired vet) thinks she had an underline issue. She was never a regular layer, and out of all 7 girls she was the only one that disliked being touched. Which I know some birds just dont like it but it was odd how she would walk up for love and then not like being held for that long. I miss her so much already.I'm so sorry she passed. I can't tell you this is what happened to your pullet, but I had a few grow outs from a specific breeding pen I had bought and hatched eggs from and they did not do well in the heat. The one would get pale and pant and be so weak, I'd cool him down the best I could. On cool days he did better, so I kept him with cool foot baths, cold treats etc but I did lose him. This line had a genetic heart defect, they had very small hearts.
It is possibly your girl had something like this which caused her to be susceptible to the heat. As @TwoCrows said, she knows you loved her and did all you could for her
Like @2ndTink mentioned above, I too have had birds with heart trouble, they tend to be weaker and can't tolerate the heat. I've had several birds die from heart failure as well. They come into this world with issues, they may not live long lives but we give them all our best and at least it was a quality life. It takes a while to get over the heartbreak, I know.
Good shade is very important. We're so humid here I haven't tried a mister but I think it would work well, just use it for the hottest part of the day and try to keep the ground from getting too wet. You don't want to accidentally create a cocci explosion.
