The Short Second Life of Bree Tanner: An Eclipse Novella (Twilight #3.5) by Stephenie Meyer
Bree Tanner can barely remember life before she had uncannily powerful senses, superhuman reflexes, and unstoppable physical strength. Life before she had a relentless thirst for blood...life before she became a vampire.
All Bree knows is that living with her fellow newborns has few certainties and even fewer rules: watch your back, don't draw attention to yourself, and above all, make it home by sunrise or die. What she doesn't know: her time as an immortal is quickly running out.
Then Bree finds an unexpected friend in Diego, a newborn just as curious as Bree about their mysterious creator, whom they only know as her. As they come to realize that the newborns are pawns in a game larger than anything they could have imagined, Bree and Diego must choose sides and decide whom to trust. But when everything you know about vampires is based on a lie, how do you find the truth?