Hamlin began her career as a gynaecologist at the Crown Street Hospital in the eastern suburb of Sydney where she met her husband, Dr. Reginald Hamlin. Responding to an advertisement in the British medical journal the Lancet, calling for doctors to work in a hospital in Ethiopia, the Hamlin’s set of to embark on what they expected to be a short mission but in turn became their life’s work.
Upon arriving in Addis Ababa, they began work at the Princess Tsehai Memorial Hospital. The Princess Tsehai Memorial Hospital was named after the Emperor’s youngest daughter