Lake County: by Lori Roy

The novel you're describing is "The Disappearing," written by Lori Roy. It's a thriller set in the 1950s that reimagines Marilyn Monroe's life and involves a teenage girl named Addie Anne Buckley, who dreams of escaping her small-town life in Florida to pursue a glamorous career like her aunt Jean, who is known as Marilyn Monroe.

Addie plans to go to Hollywood for her eighteenth birthday with her aunt's help, but her boyfriend Truitt Holt complicates things by issuing her an ultimatum: stay and marry him or leave alone. Addie chooses to pursue her dream, causing a rift between them. Unbeknownst to Addie, Truitt is involved in illegal activities tied to the Tampa Mafia. His actions put him and Addie in danger, setting off a chain of events where Addie finds herself fighting for her life against mob threats that reach her family as well.

The novel blends historical elements with a suspenseful plot, exploring themes of ambition, love, betrayal, and the dangerous allure of fame and fortune.