Sewell exhibited "A Pastoral", "A Sylvan Festival", and "Pleasures of the Past" at the Pennsylvania Academy of the Fine Arts exhibition between December 21, 1896 – February 22, 1897. She won a bronze medal at the 1901 Pan-American Exposition, a silver medal at the 1902 Charleston Exposition in South Carolina, a bronze medal at the 1904 St. Louis Exposition, and the Thomas B. Clarke prize for best figure composition at the 1904 National Academy of Design exhibition in New York for "The Sacred Hecatomb". The painting, called an "important" work by "The Independent", depicts dancing Greek maidens and children leading a procession of cattle to the sacrifice. "Harper's Weekly" commented, "These joyous figures, moving in a leafy glade into which the sunlight filters, are charming in color and rhythmic movement, and as a piece of admirably conceived and executed decorative painting it stands alone in the collection." She was the first woman to earn a major prize at the National Academy.