In 1882 Marshall was the first woman to join the faculty of Blockley Medical College, as a demonstrator in obstetrics. In her 1897 book The Woman's Medical College of Pennsylvania: An Historical Outline, she praised chairman John Huggard for offering her the opportunity, writing: "To this gentleman, more than to any other, belongs the honor of extending more fully to women the clinical advantages of this great hospital."[5] In 1886 she became an attending physician at the Girls' Department of the Philadelphia House of Refuge.[1][3]
Marshall became dean of the Woman's Medical College in 1888, after the death of Rachel Bodley.[6] During her tenure, her achievements included expanding degree programs from three to four years, increasing the number of subjects taught, and instituting an entrance exam.[2] In 1896 she oversaw the establishment of the first professorship in bacteriology and a laboratory for its instruction.[1] She encouraged students to author academic papers, and in 1895 compiled a list of over 500 such publications.[7] In 1904, Marshall's fundraising efforts resulted in the construction of Pavilion Hospital on the college grounds. From 1907 to 1913 this was expanded to the larger College Hospital. She retired as dean in 1917 and worked in private practice until shortly before her death from arteriosclerosis in 1931.[3][1]
Marshall was a member of organizations such as the Philadelphia County Medical Society, the Obstetrical Society of Philadelphia, the Medical Society of the State of Pennsylvania, and the American Medical Association.[8] She was a founding member of the New Century Club, and advocated for women's suffrage and the admission of women to medical societies.[1] She was a school board member and a school director in Philadelphia's Eighth Ward.[3]
