Princess Elsa of Arendelle. Heir to the throne. Resident mischief maker. Extremely intelligent for her age.

....And capable of magic.

She was born with powers over ice and snow. And they grow with her, even when she doesn't use them. But when she does use them, they grow faster, her power increasing along with her control.

Only eight years old, and already very powerful, though she only uses them for fun. For now.