Thanks for the query.
she might be suffering from fungal infection
Probably tinea cruris
As she is a sports person, she is prone to develop fungal infection.
Mainly due to lot of sweat and moisture.
Apply some anti fungal powder, she will be fine.
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
If the lesions persist, please meet a dermatologist
for final diagnosis