Doppelgänger

Elsa Mars knows what it's like to be over-shadowed by a sibling.
She knows what it is to have opportunities squandered by a more talented other.

Elsa had a twin sister, who went missing and was presumed dead when she was young, her twin's death never left her parents.
It was like anything she ever did was never enough, her parents longed for their dead child, they stopped looking at Elsa like parents should.

She was always one half to a broken circle.