Cough 20 days after COVID symptom onset.

Hi, My mother 59 years old had fever on 18th of April. Her doctor prescribed antibiotics, antihistamines and vitamins and her fever went down after 3 days. But due to fatigue and low bp we got her tested and she tested positive for COVID(rt PCR positive(26) on 27th of April. Her lung ct scan showed 6/25. Her blood test reports have all values normal and under range, and she tested positive for IgG antibody on 3th April. However she has had cough since 4th April night, and has been taking doctor prescribed pulmoclear tablets. After taking them, her cough has reduced, though still there to an extent. She doesn't have other symptoms. Is this of concern? Does she need any other medication? She is only having vitamin tablets now.