If the fever
is there for 5 days already, and not showing any improvement,the. Child needs further tests like CBC,widal
,malaria( if you are from India),urine routine and culture ,etc for finding the cause of fever.pl go back to the doctor for advice and examination.Blood trans fusion last year does not relate to this fever.
Ofcourse for thalssemia she must be on very regular followup and frequent Hbestimation. good luck