Cass was a competitive fencer, "reputed to have the most beautiful form of any woman in the world." She taught fencing to women at
Mount Holyoke College, She also taught privately in Newport, to young men and women in wealthy families, including the
Vanderbilts and
Astors.
James J. Van Alen was one of her fencing students. Her 1930 book on fencing included historical and practical information, with diagrams and photographs. Cass was a skilled horsewoman, and played tennis and golf well. "No mother should neglect a talent that has been given to her," she told an interviewer in 1930. "She need not use it remuneratively, but she should make it benefit the family." Cass filed for bankruptcy in 1920 and 1924, and was arrested for passing a bad check in Rhode Island in 1924. ==Publications==