Far more plausibly she has a health anxiety and never had the coronavirus to begin with. She isn’t well but it is most likely a psychological rather than a physiological condition.
My wife has something similar. Caught it in late February - at the same time as me - and _still_ has debilitating coughing fits some days, and no energy to move some days. Unless you're also going to tell me that's in her head too, and mine.