[3] Her instructors included Rachel Bodley (chemistry), Ann Preston (physiology), Emeline Horton Cleveland (obstetrics), and Mary Scarlett-Dixon (anatomy).

[1] She graduated with a degree in medicine in 1875, and due to her exceptional skill was immediately made a demonstrator of materia medica and therapeutics.

[1] Some members of the college board disputed Marshall's appointment due to her lack of experience, but she was able to overcome their objections.

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.

[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.