[1] She attended Walford Anglican School for Girls and is studying a MBBS at the University of Adelaide.
[2][3] Marshall was 18 years old when she and Eloise Hall founded TABOO in 2017, a social enterprise to help women fight the stigma of menstruation, motivated by a trip to Kenya where she saw young girls who had dropped out of education due to menstruation.
[4][5] They crowdfunded $56,000, launching a range of ethical and organic menstrual hygiene products in 2019, with all profits going to African charity One Girl.
[2][7][8] Marshall and Hall direct and manage the company, as well as visiting schools to educate students about the cause.
[10] In her speech upon receiving the award, Marshall said "Periods should not be a barrier to education.