Who is Emily Lewis from The Missionary Position: Mother Teresa in Theory and Practice and what is their importance?

Emily Lewis is a 75-year-old nurse at the time this book was published, who wrote a letter to Hitchens after his documentary film questioning the motives of Mother Teresa was released. In Lewis' letter, she describes meeting Mother Teresa in Washington, DC, in 1989. Mother Teresa was receiving an award, and in her speech, she discussed her opposition to contraception and homosexuality, frequently referring to what God wants us to think or do.