Lyndis

Lyndis, commonly known as Lyn, is one of the three main characters of Fire Emblem: The Blazing Blade, although she is not mentioned in Fire Emblem: The Binding Blade. She is 18 years old in her story, and 19 years old in Eliwood's and Hector's stories (although in the Japanese version, she states that she is 15 and 16 respectively).

(Source: Fire Emblem Wiki)