Octavia Swan was changed at the age of 17. She was changed to be a part of an army but she revolted and killed the man who changed her and then the three other newborns. Her sister, Bella Swan, didn't know of this. Her mother always called her an emo Shadow creature because of her hiding in black hoodies all the time. she and her sister moved in with her dad and that's where she came across the cullen's.