this kind of non resolving or recurring symptoms may be there in cases of sinusitis
(infection of sinuses or air spaces in the facial bones)
you should consult a ENT specialist
(ear, nose and throat specialist) to get her evaluated for this. if this is diagnosed it may need a fairly longer course of antibiotics to treat.
meanwhile, you can give paracetamol
for headache and some over the counter cough suppressant for cough (only if its dry cough
and no breathlessness is associated.
hope you benefit from my answer
thankyou for query