Tiger Lilly.: The family secret

Tiger Lilly is a series of books, written for teens and by teens.
It takes place in a small american town and involves many interesting characters who all know 'Sarah' a rather average girl, who soon realises she's not so average after all.
Mysterious things begin to happen to her and around her, travel on a fantasy journey with a powerful theme.
From a school project to an elaborate series, this book had been published for readers paragraph by paragraph on a weekly blog.