[1][2] Robinson-Duff was born in Bangor, Maine, to British mining engineer Colonel Charles Duff and his wife Sarah Robinson, a native of Bangor who, after the couple separated, moved to Chicago and later to Paris, becoming a noted opera singer and singing teacher under the name Sarah Robinson-Duff; her first pupil was future opera star Mary Garden.
After being instructed in the Delsarte system by a drama teacher in Chicago, Robinson-Duff was invited to join the touring company of famed Shakespearean actress Julia Marlowe.
[2] After eleven years of acting, she joined her mother in Paris, where they enjoyed the company of performers and composers such as Enrico Caruso, Sarah Bernhardt and Camille Saint-Saëns.
[1] Shortly after the end of the war, mother and daughter moved to New York City, where Robinson-Duff established herself as a leading voice teacher, whose many famous pupils included Vivian Nathan,[5] Mary McCormic, Dorothy Gish, Helen Hayes, Kenneth MacKenna, Catherine Calvert, Ina Claire, Miriam Hopkins, Ruth Chatterton, Mary Pickford, Clark Gable, Norma Shearer, and Katharine Hepburn.
[1][2] The Robinson-Duff approach to voice training involved elaborate vocal and breathing exercises focused on the use of the diaphragm,[6] a method humorously recounted by Hepburn (who never mastered it) in her autobiography, Me: Stories of My Life (1991).