Thanks for writing to us.
The symptoms your sister is having could be due to side effect of the oral pills
she is taking. For a viral infection, fluid repalcement and vitamin C
supplements are helpful. Anti viral drugs are not helpful in such non specific infections.
You can get her MRI
of head done to find out any other central cause of headache.
I hope this information has been both informative and helpful for you.
Dr. Rakhi Tayal