Osirium's End

Rebecca St. James' was born the child of two vampires. Growing up, she knew her family was different, but had no idea whether she carried the gene that would unlock her vampire powers. After Rebecca's home was invaded and she was attacked, she woke up an orphan-and a vampire. The Osirium's End Series begins three years after Rebecca is turned, when she discovers she's not the only one with powers...
Shards of Osiris is set three years after Rebecca was turned. She's finally close to getting her life back on the right track. Her grades are improving, she's making friends, and there's even a boy at school who wants to date her. Two, in fact. But, just as things seem like they're perfect, she discovers that she's become a pawn in a war between two vampire courts: one in thrall to ancient vampire gods and the other rebelling against them. And now, one of the two courts has targeted Rebecca's best friend Cassie. Rebecca, her friends, and both of the boys in her life will have to fight to keep Cassie safe and avoid the warring courts in Shards of Osiris.
Codex of Serket is a novelette set between the events of Shards of Osiris and Anubis Rising. In Serket, Rebecca and her friends take a day-trip to Lehigh University's library to track down a book of spells for Cassie. When they're transported to a pocket dimension to fight the same demons they thought they defeated just a few weeks before, though, they're each forced to face some of their greatest fears.
In Anubis Rising, Rebecca must fight the Osirium directly, and discovers a new threat that she unwittingly released when she defeated the Osirium in Shards of Osiris. She also meets an old friend who stirs up powerful emotions that she'd thought she'd long-since left behind. Failure could destroy her family, and even end the world, but Rebecca St James has no idea how she'll assemble the power she needs to take on Isis and Osiris.