Switched (My Sister the Vampire #1)
When Olivia Abbott moves to town, she's excited to join the cheerleading team and make new friends. Then she meets Ivy Vega. At first, Ivy, pale and dressed all in black, looks like Olivia's opposite. Then the girls look beyond the glittery pink blush and thick black eyeliner to discover they're identical--identical twins!
Olivia and Ivy are brimming with plans to switch places and pull every twin trick in the book. But Olivia soon discovers that she and Ivy aren't exactly the same. Ivy's a vampire. And she's not the only one in town.