Thank you for your query.
Your description suggests a viral infection which can give rise to all the symptoms that you have enumerated. Infectious mononucleosis
is also a viral infection but the blood smear examiination suggests some typical findings. I suggest that you get her examined by your doctor which is always better.
I hope I have answered your query to your satisfaction.
Wishing your daughter an early recovery.
Rajiv K Khandelwal