Some of the infections can take bit longer to recover from and probably that explains the recurrence of fever
Are there any other symptoms like cough/cold/urine problems etc?
I would advise to continue symptomatic treatment - Paracetamol
for fever. Make sure she is eating & drinking well.
There are more symptoms associated with Leukemia
and physical examination by a doctor can pick up signs which are suggestive of Leukemia. Blood tests do reveal very high white cell count with presence of immature cells in Leukemia, which is not present in the blood test your daughter had.
Since the fever has been recurring over last 2-3 weeks, it is advisable that she gets seen by a doctor.
I don't feel it is serious.