Nocturne Academy by Suneowara

Blurb:

Growing up thinking she had an illness, Cleofa spent her whole life without setting foot outside. Books were the only ones keeping her entertained, and the book that caught her attention the most was called ‘The Gifted.’
It was a book about people who are called gifted—who inherited gifts from different Greek gods and goddesses. At first, she thought it was just a fantasy story, until she encountered one herself.
Thinking it was just an effect of her illness, she was taken to a place where she could be cured. But it wasn’t a hospital nor a center, but an academy.