The Granger Girls - The Hayford Murders Duology, #1

"In this world, popularity is everything. And I will settle for nothing less than queenship."As the only child of two of London's most prestigious lawyers, Kate-Camille Granger has grown up expecting the world, so when she finds herself a nobody at Hayford Independent - the elite all-girls school she attends alongside the daughters of some of the richest people in the world - she comes up with a devastating plan to get to the top.
Kate won't work alone, though, and it doesn't take long to find a vulnerable group of classmates to help her: a group she will call "The Granger Girls."Under Kate's control, these five girls soon find themselves pulled into a scheme which will bring terror to every student at Hayford, as they commit crime after horrific crime. But how long can they take it for? How long will Kate be able to rule before The Granger Girls finally snap?...