Who is Hannah Snow from Soulmate from Night World No. 2: Dark Angel; the Chosen; Soulmate and what is their importance?

Hannah Snow is a sixteen year old girl who thinks she is going crazy because she has begun to find notes in her handwriting that warn her that she will die before her seventeenth birthday. However, with help from a therapist, Hannah discovers that she has been reincarnated dozens of times. In each of her previous lives, Hannah was killed before her seventeenth birthday by a vampire pretending to be her soulmate, Thierry. When Hannah learns the truth about her past lives and Thierry, she sets out to find him, only to find herself kidnapped by her worst enemy. Hannah is nearly killed again, but manages to protect herself and get the guy.