Herpes Doctor

My 12 year old daughter was diagnosed with a blood test last year. Approximately 12 months later, she is sick again and had another blood test positive for mono. I have read this is not possible. Help??? She began with a positive influenza test, an x-ray showing a bacterial infection in one lung and the first mono test negative. She had a fever, congestion, vomitting, fatigue, and sore throat. Her white blood cell and platelet counts were down. I am afraid she is "getting lost" in the medical community. I have scheduled her with a hematologist. Am I doing the right thing or over-reacting?