"The Echo Wife" is exactly the kind of book I would pick up at my library based on the striking cover, interesting title, and compelling description. While I'm not sure from the first three chapters whether Sarah Gailey's book reminds me of Shirley Jackson or Ruth Ware, I don't hold that against them. They are very effectively carving out their own niche in the unreliable-female-narrator-with-a-mysterious-air genre, all while folding in elements of science fiction in a palatable way.
Evelyn Caldwell is not necessarily a protagonist who gives off warm and inviting vibes, and that might be off-putting to some, but it makes sense given the deterioration of her marriage due in part to her own career in scientific innovations.
I'm curious to see how Evelyn evolves and to see more interactions between her, Nathan, and Martine.