The Secret Poet by Georgia Beers

Morgan Thompson is content with her quiet life, her close family, and her job managing her brother Perry’s medical practice. She even helps him navigate online dating, rewriting his messages to make him sound more confident. When new pharmaceutical rep Zoe Blake arrives, Perry is instantly smitten and relies on Morgan more than ever. Zoe is beautiful and a little mysterious and not particularly interested in Perry, so Morgan decides she needs to understand her before playing matchmaker. Soon she is talking books and movies with Zoe and writing to her as Perry, and the more she learns, the more she wants to know, until she begins to wonder if she is wooing Zoe for her brother or for herself.