So my basic outline for Sabriel's AU backstory is this. Sabriel was raised in northern England by her father and his coven. She's a powerful but inexperienced witch whose strength lies in dealing with ghosts and counteracting Dark magic... and who arrived in London recently to try to learn where her father's vanished to. (Her father being a powerful witch who had a reputation for fighting off those who used dark magic and was a talented medium. He would have had a lot of friends/acquaintances/enemies if people want to say they know Sabriel through her dad.

She's generally stoic and serious but actually kind of playful underneath that, and generally respectful when dealing with other supernaturals, though she's somewhat pitying of werewolves, wary of vampires, and VERY wary of the fae.