Unless her spo2 falls further a CT is not required. Also you could get her inflammatory markers (IL6, serum
ferritin, CBC, d dimer, LDH etc) done. There have shown to have a role.in predicting the prognosis for the patient.
Most of all , keep calm. Check the spo2 at regular intervals and a spot of minor exercise (walking about the house for about 5 minutes). In case of any sudden onset breathlessness lie prone and so deep breathing.
Stay alert. Keep a lookout for the symptoms.