The Short Second Life of Bree Tanner Book by Stephenie Meyer

Bree Tanner, a self-described “vampire nerd” first introduced in Eclipse, lives in terror in a coven of newborn vampires. She is a member of Victoria’s vampire army, and as that army closes in on Bella Swan and the Cullens, she finds her first friend and discovers a truth about daylight.
While fans may know how it ends, they don’t yet have the full story: Bree’s tale of danger, mystery, and romance is one for the books.