If she is impacted, are the greens still OK? She does enjoy them! (though I left the kale in my work fridge and will need to go out for more) Since I don't know whether it's blockage or yeast (or both?) I don't want to make either scenario worse. If it were yeast, wouldn't she have responded a bit by now even though the copper treatment wasn't perfect?
She's ignoring the wet feed (which is mixed layer and grower), so I'll remove it. The other girls might like it, though they ignored it yesterday.
Finally, Ruby hasn't laid in months. HOWEVER... I think she may have had a mini molt earlier and is in the full molt now. Since this is only my third year of keeping chickens, I'm still learning the molt patterns (or lack thereof!) I think I am mentioning the laying because deep down I am aware the crop may be a symptom of something else... hoping I can help her clear it...
Birds have to eat. Impacted or not. Greens may move slow, but they won't feed yeasts.
It takes a minimum of 5 full days on the Copper to work. Copper Sulfate can sometimes take 7 full days to kill off yeast. I've seen it take 10 days. So a few days is not enough to judge.
And yes, many times other internal issues are going on like internal laying, reproductive cancer or Liver disease
All these are extremely common in hens, swellings from any of these can close off or slow the emptying of the waste and crop. And of course any disease will lower immune function causing yeast infections all throughout the body.