The symptoms of the patient suggest a long term fever
for more than a week, then some more tests need to be done. Her ESR is raised suggesting that infection is present.But repeat some blood tests like CBC, platelets,widal test
antigen and malarial antigen,urine culture. Her chest xray should rule out pneumonia
. I believe that antibiotics need to be started.So do the above tests and consult a doctor with the reports. As it is,her immunity is low due to the cancer treatment so dont neglect these tests.