So my daughter (7) is humoring pops and will play in the 40k campaign I'm going to run if she can play Elsa. To accommodate this I've worked out this background:
Sanctioned Psycher who is the queen in absentia of the agri-planet Arendelle. After the events of the movie an Inquisitor (hopefully another PC) came to the planet and recruited her to their retinue. She put her sister in charge when she left with the planet.
This will allow her to work from a place she's familiar with and will hopefully make her feel comfortable. I'm slightly stuck on her powers. At this point I'm thinking just flipping the fire powers to be cold powers. Ultimate effects unchanged, just how they manifest.
What I'm hoping is someone has actually done cold based psycher powers and can point me to to them. I'm also open to suggestions as to better ways of accomplishing Elsa for her if people have such suggestions.