Consider Me Gone by Jane Thornley

What if souls have memories that survive across the centuries? As a student of history, Romy always dreamed of being a tourist in time. That is, until the day she’s dragged back to 18th Century New Orleans to walk in another woman’s shoes, live another woman’s traumas, and love the man the other woman plans to betray. And then Romy realizes that the woman of the past is her still wrecking havoc today.
Romy works too many jobs—part-time tour guide and occasional performance artist included. So when she begins hearing and seeing things not of this century, she puts it down to fatigue. But things just keep getting more baffling, more destructive. One moment, she’s Romy in the 21st century and the next she’s Claire, an Acadian orphan spying against the Spanish two hundred and fifty years earlier.
Suddenly it feels more like she’s a tourist in hell.

No one believes her, not even Dr. Adrian Countway, her thesis advisor and the man she loves. Their attraction is undeniable and yet he resists. He’s certainly not about to believe that he’s the reicarnation of the first Spanish governor of Louisiana anymore than he believes that Romy’s an Acadian orphan inciting a revolution. But how can she explain making a lurid pass at him in a public bar or pushing a client down the stairs in full view of everyone? What’s worse, how does her purse end up beside a murder victim on Dauphine street with her pocket knife plunged into his chest?
And then the tap-tapping of a cane begins ghosting Romy’s heels and suddenly she’s being chased by an unseen enemy in two timelines. The souls of one’s victims will haunt your spirit across time itself, claims Louisa DuPre, the spiritual advisor of half of New Orleans and a force to be reckoned with. The only way to cleanse a toxic soul is to face it’s trauma and untangle the lives it’s destroyed in the original timeline. Either Romy returns with Claire to the 18th century to repair the damage done or she’ll lose everyone and eveything that matters in the 21st … including herself.