Hit Girls: Gangland Girls Book 3 by Dreda Say Mitchell
Two kids are murdered...Their gangland family want revenge. Ten-year-old twin sisters are murdered outside their school. But they aren't just anyone's kids, they are gangster Stanley Lewis' daughters. When a rival gangster is arrested Stanley vows to take revenge. But his dad, feared villain Kenny Lewis, thinks there's more going on. So he contacts the one group of people who he trusts to help him find the truth...Jackie, Anna, Roxy and Ollie. Four women with shady pasts who take the cases people don't take to the cops. They enter a world of easy sex and even easier violence where everyone, including the Lewis family, are hiding secrets. Then Jackie's son, a friend of the dead girls, disappears.