FishMtFarm
Emu whisperer
I believe it is coccidiosis. You said they had mites and the stress of the mites feeding on your birds can and will cause a coccidiosis out break. Any weakness, stress or illness will cause outbreaks even in mature flocks. Continue the corid at 5 days on, 5 days off, and 5 days on again. Baby can have it too. She can be reunited with mom since they are all being treated but at this point, mom might just be done with her broodiness now.