Dorothy Ochtman received her A.B. from Smith College in 1914 and then did graduate work in art history at Bryn Mawr. She attended the National Academy of Design School (1916-19) and studied with her father Leonard Ochtman. She received a Guggenheim Travelling Fellowship and studied at the Ecole Americaine des Beaux Arts at Fountainbleau and at the Academie Despujols (1927-28).
She worked in a post-impressionist style specializing in flower pieces, still life and portriats. Her work was handled by the Grand Central Art Galleries where she had exhibitions in 1931, 1934 and 1946. In 1945 she married William A. DelMar, an electrical engineer.