Camellia "Camellius" Bale

About

Her stepmother Anastasia forces Camellia to become "Camellius," posing as another son for the House of Bale in case their chronically ill eldest child Kieran should die. Though Camellia doesn't want to do this, she is made to believe that her own life and the life of her mother are at stake if she refuses.

(Source: Finding Camellia Wiki)