Lathrop was born in Lawton, Oklahoma, on June 16, 1915. She attended Oklahoma A&M, where she earned bachelors degrees in home economics and chemistry. She met her husband, Clarence Lathrop, while they were both studying for masters degrees in chemistry.. They married in 1938 and had five children.
Upon completion of their master's degrees in 1939, the couple first moved to New Mexico and then to Wyoming in 1941. Lathrop became a research assistant at the University of Wyoming where she focused her efforts on research pertaining to poisonous plants that grew on the Great Plains. In 1944, Lathrop and her family moved to Chicago where Clarence pursued a medical degree at Northwestern University. They  divorced in 1976.