 In 1944, directly after Gerald's death, she returned to her pursuits at Columbia, this time studying ethnobotany.In 1958, Margaret completed her dissertation, "The Ethnobotany of Pre-Columbian Peru as Evidenced by Archaeological Materials", and received her Ph.D.Upon completing her studies at Columbia, Margaret worked for the Harvard Botanical Museum as an unpaid associate until her death on November 2, 1985.