Thanks for posting your query on DoctorSpring.com.
I can understand your concern and I am sorry for the delay in my response.
This seems to be a fungal infection called Tinea.
It requires an oral anti-fungal tablet called Terbinafine (250 mg/day in 1-2 divided doses for 2-4 weeks) and Terbinafine cream to be applied on the affected areas, twice a day.
You will need a prescription from a doctor for these medications.
In case it doesn't resolve with these medications in two weeks, it would be best to consult your dermatologist who can physically examine her and confirm the diagnosis.
Please let me know if you have any queries.