Elsa

Elsa is a character on Once Upon a Time in England.

She is the sister of Queen Anna and King Kristoff, the daughter of Queen Gerda and King Kai and niece of Ingrid the Snow Queen. She later returns in "Heroes and Villains: Interlude" as John Watson's love interest

Elsa  is based on the character of the same name from the Disney film Frozen and on ''Mary Morstan. ''

After Second Curse
One day, Elsa begins missing her friends back in Storybrooke, preferably John Watson. She abdicates her claim to Arendelle with Anna and Kristoff taking control. In between the six weeks, Elsa returns to Storybrooke unconscious to the shock of John and Emma. However, she and John admit their feelings through a true love's kiss (Heroes and Villains: An Interlude)

Before Third Curse
Getting up to the fact that John and Emma are now both Dark Ones, Elizabeth asks what could it mean now that her aunt and dad are dark Ones, Elsa remains unclear, but promises Elizabeth to make it her mission to save her boyfriend and her best friend(The Dark Swan)