The Replacement Wife

The concept is so chilling and specific — I wonder if it was based on real cases or purely fiction. How did the author come up with this idea?

The relationships seem tense and fragile, almost too easily formed. Is this a reflection of real trust issues or a storytelling choice to ramp up suspense?

The alternating viewpoints kept me guessing, but I’m curious if that was planned from the start or evolved during writing.