During childhood, Heger's family moved west to Belvedere on the San Francisco Bay, where she spent her youth.
[1] Heger received her bachelor's degree in 1919 from the University of California, Berkeley, becoming a graduate student in astronomy.
[1] After marrying C. Donald Shane in 1920 she completed her PhD in 1924, writing a thesis under the supervision of W. W. Campbell at Lick Observatory that was one of the first papers to recognize the sharp, stationary Na I absorption lines in the spectra of distant binaries as interstellar in origin.
[1] At the end of World War II when her husband became director of Lick Observatory, Heger became a well-known scientific hostess and was remembered for her generous hospitality.
[1] Mary Lea Shane died on her 86th birthday of a heart attack at her home in Scotts Valley, California on July 13, 1983.