Endless. The Serenity Series, #5

The fifth and final book in the 'Serenity' series:On the morning of her thirteenth birthday, half vampire Elizabeth Bandores wakes to find she's crossed the boundary between childhood and becoming a young woman. Not only that, the sunlight makes her head pound, and her hearing and sense of smell are suddenly sharper. A horrifying incident makes her wonder if she's a girl or a monster, and the world around seems to agree as a terrifying storm erupts over Los Angeles.
Serenity has no idea how to handle her rapidly changing daughter, but she knows one thing; Elizabeth needs her father around. As Los Angeles is plunged into darkness and danger, life is about to get a lot worse, not just for Elizabeth but for Serenity and Sebastian too. A balance has been disrupted and the world as they know it may be about to change...