You are downvoted for passing off your uneducated (in the field of health) opinion that her illness was coronavirus as fact, and for implying that antibiotics somehow could help with the coronavirus directly (i.e. in fighting the virus not preventing secondary infections) in any way (they can't).
It can't already be confirmed if the labtest is not completed yet. It sounds like you still misunderstood the nurse.
They're doing a labtest for Coronavirus because she's been in contact with a nurse who's been in contact with a Coronavirus patient. It is just standard protocol to get tested in that case.
