Not Quite Dead Yet by Holly Jackson

In seven days Jet Mason will be dead. Jet is the daughter of one of the wealthiest families in Woodstock, Vermont. Twenty-seven years old, she's still waiting for her life to begin. She'll do it later, she always says. She has time. Until, on the night of Halloween, Jet is violently attacked by an unseen intruder. She suffers a catastrophic brain injury. The doctor is certain that within a week, she'll suffer a deadly aneurysm. Jet never thought of herself as having enemies. But now she looks at everyone in a new light: her family, her ex-best friend turned sister-in-law, her former boyfriend. She only has seven days, and as her condition deteriorates she has only her childhood friend Billy for help. But nevertheless, she's absolutely determined to finally finish something: Jet is going to solve her own murder.