Flora

Flora is the older twin sister of Felicia and a maid for the Nohr royal family, serving Corrin. She is the eldest daughter of the Ice Tribe's chieftain, Kilma. Their father always treated Felicia more favorably due to her superior fighting ability, however, Flora was still expected to become the Ice Tribe's next leader. The player can recruit her in the My Castle once the Fire Orb reaches level 3 after Chapter 18 of Conquest. In Revelation, the player can recruit her once the Ballista, Fire Orb, or Launcher reaches level 3 after Chapter 22.

Although she is Corrin's servant, Flora and Felicia were actually kidnapped by King Garon as hostages to prevent the Ice Tribe from staging a rebellion against the Nohrian Kingdom. Flora was aware of this while Felicia was not. Forced into servitude for Corrin, she eventually became accustomed to her role, becoming an exemplary maid. She also struck up friendships with Corrin, their combat instructor Gunter and Jakob, Corrin's butler.

(Source: Fire Emblem Wiki)