This is called hand foot mouth disease. Its a viral illness, seen in many children. It will go away on its own in few days.
Next Steps
just give her rest, plenty of oral liquids and paracetamol for fever if she has.
if it doesnt go away in few days or she develops any other problem such as vomiting/ loose motion/ bleeding then u need to see doctor.
Health Tips
dont send her to school or playground for few days.