The Girl-Who-Became-Harry-Potter

Harriet is an orphan who has lived all her life in the foster system. Her only respite during childhood has been reading the 'HP' books. One day, while reading once again 'The Philosopher's Stone', she's struck by lightning. Instead of dying, she appears inside the cupboard under the stairs looking like a six-year-old and with a familiar lightning bolt shaped scar on her forehead.