It is up to you, but there are about 5 common diseases. The sickness you had before, may not have been coryza, but it could have been. Mycoplasma (MG,) coryza, ILT, infectious bronchitis, and aspergillosis are common ones, and each one can have secondary bacterial diseases present at the same...
I mam so sorry to tell you that she may have infectious coryza, a chronic respiratory disease. It is never cured, and although she may improve, she may get sick again and again. She and the other chicks she has been with should be considered carriers for life.
Do you have other chickens who...