The Secret Life of Sparrow Delaney by Suzanne Harper

How do you ignore a ghost?

Sparrow Delaney absolutely, positively does not want to be a medium like her six older sisters, her mother, and her grandmother. She does not want to see, hear, smell, or talk to ghosts. If she sticks to her rules and doesn't let anyone know that she can do all those things—everywhere, all the time—Sparrow just might pass as a normal tenth grader at her new high school. She makes a new best friend and meets an irritatingly appealing guy in her history class. But when another boy catches her eye, all Sparrow's dreams of being ordinary go up in smoke. Because this boy is a dead one—a persistent, charming, infuriating ghost, who won't let her be until she agrees to help him Move On.