Parsons became head nurse at the MGH School of Nursing after graduating from the school. She later became Superintendent of Nurses at MGH from 1910 to 1920. During WWI, she served as the chief nurse of Base Hospital No. 6, an MGH-led war hospital in France. Today she is known for her history of the MGH School of Nursing, but in her lifetime she was beloved as a nursing teacher who wrote about contemporary issues in nursing.