Gulielma Fell Alsop was the oldest child of the Rev. Reese Fell Alsop and his wife Mary Lee Spring. Her younger sister became the popular writer Mary O'Hara. She grew up in Brooklyn, New York, where her father was the rector of St. Ann's Episcopal Church. She graduated from Barnard College and the first medical school for women in the USA, Women's Medical College in Philadelphia. In 1908, she went to Shanghai, China as a medical missionary and worked at St. Elizabeth's Hospital for Women and Children there. She returned to the USA in 1917 and became the college physician for Barnard College for 35 years. She also co-wrote several books for young women, including She's Off to College (1940), She's Off to Work (1941), She's Off to Marriage (1942), and Arms and the Girl: A Guide to Personal Adjustment in War Work and War Marriage (1943) all with Mary F. McBride. Other independent works included a memoir, Deer Creek: The Story of A Golden Childhood (1947); History of the Woman's Medical College: Philadelphia, Pennsylvania, 1850-1950 (1950); and A Gift for Santa Claus (1970).