Medli ( Medori?) is a member of the Rito. She trained long and hard under Prince Komali's Grandmother in order to be given the task of becoming the attendant to Valoo, the guardian deity of the Rito and of Dragon Roost Island. Despite her training for that specific task, with the help of Link, she eventually discovers that she is the Sage of Earth.
Medli is a very dedicated young girl, putting effort into everything that she does. Her greatest treasure is the harp that she carries on her back.
(Source: zelda.wikia.com )