Although she neither married nor had children, Nellie Quander led a dynamic life. She taught in the D.C. . Public Schools from 1901 until 1950, and earned a masters degree in Political Science from Columbia University, New York, in 1914. Her brilliance and people skills were legend, and caught the attention of many people, including whites, who quickly appreciated that she was special. In 1916 she was appointed as a special agent for the U.S. Department of Labor, Children's Bureau, a position that required her to take a one year leave of absence from teaching. She studied social work at New York University, economics at the University of Washington, Seattle, and attended Uppsala University, Uppsala, Sweden, earning a certificate from each of those institutions.

Among her many active memberships was the Board of Directors of the Phyllis Wheatley YWCA of Washington, D.C., where she worked with Mary McLeod Bethune, Mary Church Terrell, and Dorothy Height. She also held many responsible positions of leadership with the Lincoln Temple Congregational Church, the Howard University Alumni, and the D.C. public schools. She knew Frederick Douglass, as her younger brother, Charles Calvin Quander, befriended Mr. Douglass on the sidewalk in front of their family home located on Georgia Avenue, at the edge of Howard University.