http://fireemblem.wikia.com/wiki/Severa
Severa is the daughter of Cordelia and can potentially be the older sister of Morgan if Cordelia married the Avatar, otherwise she is an only child. In her childhood, she grew up in the shadow of her mother's legacy. Despite her best efforts to show any sign of prodigious skill, her attempts were considered inferior to Cordelia's natural abilities. One day she got into an argument with her mother, questioning if she loved Chrom more than her. Cordelia reassured her by telling her that she fights to protect someone special to her. Severa still believed that her mother meant Chrom. However Severa would later regret this final argument as Cordelia tragically died in the battle following that conversation. She was given her mother's ring as her only memento left of her. Severa joined Lucina and the rest of the children to return to the past to prevent the ruinous future.