The Ice Queen of North Mountain

Elsa always loved using her magic. Even as a child she was always practicing and pushing her limits. Her little sister Anna loved watching her magic as well. She would beg Elsa to use her magic. To sneak out and play in the snow and ice she commanded. And Elsa loved to do so. She would spoil her sister with snow days, ice skating, snowball fights and building snowmen.
One night though, she accidentally hit Anna in the head with her magic, and in that moment, fear for her sister's safety crept in and sent her powers haywire. Their parents took them to the Trolls, and Anna was healed, though her memories were altered. All memory of her sister's magic was wiped clean from her mind. Elsa was warned that she would only get stronger as she grew, and that without control, her powers would become dangerous. She remembered the fear that sent her powers spiraling out of control after she hurt her sister, and knew that she had to master her magic, or she'd risk hurting people again.

...Her parents however, took different meaning from the Trolls warning. They believed that other people would fear Elsa's power, and she would be in danger from those who feared her. They told her not to use her magic anymore. To control it by way of restraint. Though Elsa wouldn't disobey their request to their face, she would still practice in secret. She knew that holding her powers in would not help her control them. And she knew that if she couldn't control them, she might one day put someone in danger again.

The hardest part though...Was having to be separated from Anna. Because of her anger at being forced to practice in secret the magic that she once used freely, her magic would sometimes slip from her control. And because their parents believed that Anna would be better off not knowing about Elsa's powers, they were no longer allowed to spend time together.

They believed it was for the best, but it was a mistake. Every time Elsa had to shut Anna out, her magic would slip and the temperature in the kingdom would drop. Every time she had to tell her to go away, ice would creep along parts of the castle. And every time Anna would stand outside her door, begging Elsa to build a snowman with her, the friendly snow flurry outside would whip up into a vicious snowstorm.
Elsa hated being separated from her. And the more her anger grew at that, the more her powers would slip.

She eventually became convinced that if she was simply allowed to practice her magic freely, and if she was allowed to be honest with her sister, she would finally be able to master her powers. She begged her parents to let her practice again. To let her tell Anna the truth. But when they questioned if she could really control her powers, her temper flared again, and she filled half the room in spikes of ice.

Her lack of control proven, the King and Queen told her that it would be too dangerous to practice her magic. And that until she could control it, it was too risky to let her close to her sister again.
But Elsa had had enough. She couldn't hold herself back anymore. She refused to be restrained. She knew the only reason she couldn't control her magic, was simply because she wasn't allowed to try. She stormed from her parents room, and instead of returning to hers, she left the castle, and made her way to the mountains.

She would be a prisoner no longer.