Darla's Story (Ashfall, #0.5)

Darla Edmunds has faced a lot of challenges in her seventeen years: Her dad died in a farming accident when she was fourteen. Her mother retreated into hyper-religiosity, leaving Darla to run the family farm almost single-handedly. But those struggles pale in comparison to the one she faces after the Yellowstone supervolcano erupts, plummeting the world--and Darla's small corner of Iowa--into a cataclysmic natural disaster.