For your daughter, you may give Acetaminophen
every 6 hours for 2 to 3 days in right dosage. This will help for her headache too. For nasal congestion
and occasional cough, you may give Tab. Cetirizine
10mg- half twice a day for 3 days. You may also ask her to try steam inhalation.
It might be a viral rhinosinusitis. In such a case she will be okay soon.
But if she develops high grade fever
, her appetite is poor, she is lethargic, cough is distressing, nasal discharge becomes purulant, headache is severe, she develops vomiting
etc- please do not hesitate to visit your doctor.
Hope my answer helps you.
Wish your daughter a speedy recovery.