When my SWCAH daughter, now 15, was 7 years old she had mono.  It all started when she got a stomach bug and landed in the hospital for a few days.  After her release, she just didn’t seem to bounce back like usual.  It was late spring early summer ... shcool just got out.  She typically loved being outside and was very active.  But she would go out to play and come in and lie down ... wouldn’t /couldn’t ride her bike ... wouldn’t/couldn’t play soccer etc.  I knew something was really wrong.  She was achy and slept a lot and rarely went outside.  Went for bloodwork and she was tested for mono.  We spent most of that summer recovering.  We were lucky that she was young and didn’t have to miss school.  She really had the whole summer to recover.  Keep us posted.