The Sharp Time — Mary O'Connell

Sandinista Jones is a high school senior with a punk rock name and a broken heart. The death of her single mother has left Sandinista alone in the world, subject to the random vulnerability of everyday life. When the school system lets her down, her grief and instability intensify, and she ponders a violent act of revenge.
Still, in the midst of her crisis, she gets a job at The Pale Circus, a funky vintage clothing shop, and finds friendship and camaraderie with her coworker, a boy struggling with his own secrets.
Even as Sandinista sees the failures of those with power and authority, she's offered the chance to survive through the redemptive power of friendship. Now she must choose between faith and forgiveness or violence and vengeance.