My 12 mo old daughter's WBC count was 22,200 cells/uL?

My daughter went to the doctor for her 12 month physical last week. She was happy, healthy, & had no fever, runny nose or other signs of infection. Her white blood cell count came back twice the normal range (22,000 cells/microliter). I have to wait a month to restest her. Is this number indicative of leukemia or would you expect it to be higher?