I'm very sorry to hear that you've had such heartbreak with your dear girl. You've made a very difficult but responsible decision (and selfless) after trying very hard with her. I commend you for that, and thank you.
She'll certainly be surrounded by a flock to greet her when she arrives.
Please do something nice to take care of yourself. After caring for an animal (or person) for a while, suddenly not having to causes an odd sort of stress and anxiety. Take a nice bubble bath with music playing, light a pretty scented candle in her memory, let yourself cry (we understand that it wasn't "only a chicken") to get it out, take a quiet walk, or even when you're ready go enjoy your other blessed (to have you as a mom) and healthy chickens.
Lots of hugs.
Nathalie