Whispers of Dead Girls by Marlee Bush (Author)

Ten years have passed, and Ren Taylor is back at square one, having accepted a job at her old high school. She'd hoped to make peace with the past but now she's thrust back into it: her murdered teenage sister is still immortalized in town, and Ren can't stop seeing her wherever she goes. She's dogged by the scandal that ruined her childhood and killed her sister.