Origin Story?

Heulwen, age 17, 17th Century 

Running, she was running. Blood soaked through her black dress, and she was breathing heavily. No one was chasing her; she had made sure of that when she had left the cabin. She saw it, the room in her mind. The man who had promised to teach her all he knew lay there, dead. His lifeless eyes stared at nothing, and the cauldron was bubbling next to him, a circle made of blood drawn on the floor where she herself had lain minutes before she cast the spell. But she had to, she told herself over and over; she wasn't going to let him kill her. She stopped, leaning against a tree for a moment, gasping for air. She looked down at the heavy book she carried under her arm. His spell book…no, her spell book. It was hers now, and it held everything she needed to know; her mentor had kept it safe, even from her curious eyes. If she hadn't seen it, or been able to reach it, it would have been her dead in that cabin, and that man, that man would have stolen her life and her magic.
She winced at the pain that came from her chest, from the cut that had brought her close to death. Peeking into her dress, she could see it mending itself, healing her wound. What have I done? She blinked, her eyes moving from the closing wound to the book. She flipped it open to the blood-stained page she had cast the spell from. Reading over the words she had recited in the cabin, her eyes then fell on what she had feared. The consequences stared back at her in scribbled writing.
(WIP)