What should I know about low white blood cells count

Hello. My husband and I are pretty concerned for ours daughter’s health. About a month ago she cached a bad flu. This condition lasted very long and we take her to a doctor. He prescribed her some antibiotics and that’s all. She has recovered from flu but some symptoms stayed.
She was not eating, had a constant fever and was awake for a mere 4 hours a day while sleeping the rest. I took her to her GP again and he found that her low blood cells count is pretty low.
What are the long term effects of low white blood count? Will she be catching illnesses more often?

I know some facts about blood cells tests because I had an opportunity to learn from a good friend of mine who is doctor. You have reasons to be worry because white blood cells play an important role in the immune system of your daughter.
I will tell you the truth -an unusually high white blood cell count can indicate an infection, hypersplenism, bone marrow depression or primary bone marrow disorders such as leukemia.
You should ask again for complete blood count because there are several types of white blood cells that normally appear in the blood: neutrophils, eosinophils, basophiles, monocytes and lymphocytes. Peak of any of these can indicate on some specific disease.

I have recently had tests showing high white blood cells, especially lymphocytes, im waiting for them to ring me back confirming what is wrong. Im constantly tierd also. So anyone know what this may mean?