The Van Alen Legacy by Melissa de la Cruz

The Van Alen Legacy is the fourth novel in the Blue Bloods series, was published on October 6, 2009 in a series of vampire novels by Melissa de la Cruz. The series is set in Manhattan, New York. There are six books in the series: Blue Bloods, Masquerade, Revelations, The Van Alen Legacy, Misguided Angel and Lost in Time. A companion novel, Keys to the Repository, was released on June 29, 2010. Bloody Valentine, another companion novel was released on December 28, 2010. The final book, Gates of Paradise,and also Blue Bloods graphic novel are to be released in January 2013.
Schuyler Van Alen has had trouble fitting in at Duchesne, her prestigious New York City private school. She prefers baggy, vintage clothes instead of the Prada.
Schuyler survives with the help of her best friend, Oliver Hazard-Perry.
Schuyler's mother, Allegra, has been in a coma for years and her father, Stephen Chase, is dead. Schuyler lives with her grandmother, Cordelia, in a rundown brownstone mansion in upper Manhattan. Although they share a home, Schuyler receives little affection from her grandmother, the only family she knows.
Mimi Force is the "It" girl at Duchesne. She is said to be the most beautiful girl in New York's history. Mimi and her twin brother Jack are the most popular children at their school. Their father, Charles Force, owns a series of businesses and is influential in New York City.
Bliss Llewellyn is a new girl at Duchesne... (Summary by Wikipedia)