If you think she is suffering and has little or no quality of life, then yes. It's always a hard decision. I leave mine with the flock as long as they are eating, drinking, basically acting like a normal chicken, albeit often a bit slower. Once they no longer want to eat or drink, isolate themselves, are acting obviously unwell, or get attacked by flock mates, then I euthanize rather than let them suffer. Sometimes they will spend a lot of time in a nest box, basically hiding in a quiet, dark place, others will do everything in their power to remain with the flock. No two birds are the same, I've had some live for quite some time with reproductive problems, I've had some not last more than a few days once they become obvious. But when suffering is obvious with no real hope of recovery, then I think it's a kindness not to let them slowly waste away. Sometimes you think they are doing ok, and they will suddenly pass and you find them, they are so good at hiding it.
