Welcome to HealthcareMagic forum.
To clear your doubt and get reassured you can get a dengue
blood test done .
Even though her platelets are normal it's best to get a confirmed diagnosis if she has on and off symptoms.
As of now there is no specific cure for dengue so even if it's detectected your child will be advised rest , plenty of fluids and if required supportive therapy like for fever
, itching etc . But in dengue positive patients repeated monitoring of platelets is very important to check for further platelet drop.Just one normal platelet count
cannot rule out dengue . So you can go ahead and get her tested.
Hope I have answered your query.
Wishing you good health.