Wimmer learned Spanish in Spain, where she spent four years growing up. She studied Spanish literature at Harvard. After graduating her first job was at Farrar, Straus & Giroux from 1996 to 1999 as an assistant and then managing editor. While there her first translation was Dirty Havana Trilogy by the Cuban novelist Pedro Juan Gutiérrez.
She then worked at Publishers Weekly, before the demands on working on Bolaño's books became full-time. "My reason for going into publishing in the first place was that I had decided in college that I would never be a fiction writer, but I knew I wanted to be as close to books as I could. Publishing was one way, and translating turned out to be a better way for me."