tb lymphadenitis

My daughter aged 17 is suffering from tb lymphadenitis.she had FUO and serum ADA was 59 and ESR 75 ,after start of treatment She was put on 4 drug therapy for 2 months and responded well.fever had gone but during end of second month she got swelling on neck on both sides with severe cold and tonsilitis also.she was given levofloaxcin for 5 days with some other med for throat and she was ok .The continuos phase was started after 2 months and HRE was given .in third month she got severe cold and same swelling but low intensity.now at the end of fourth month she got low swelling with severe cough with white sputum for two -three days. doctar has started levoflaoxin 500 daily with already existing HRE drug.coughing has reduced considerably .Is she recovering or is this deterioation .why levofloaxin has been started.