Callie is protagonist of the story. Raised solely by her father, she grew up mostly in the human realm. Circumstances force her to go into the Spirit World where she finds out some interesting facts about herself and her family. Callie is a tomboy, Her stature usually has this distinction. She's not afraid to get rough if she has to. 

I want you to be able to play her both when she's a child and a teenager, since there are flashbacks in the beginning, and it starts off when Callie is still a young girl and not a teenager.