She received a master's degree from the University of Pennsylvania, where she studied composition with Vincent Persichetti and George Crumb.
In 1959 she received a two-year Fulbright Scholarship to Florence, Italy, to study with Luigi Dallapiccola.
She held positions on the faculty of the Oberlin College Conservatory of Music and Yale University and then became a professor of composition at Wellesley, Massachusetts in 1976.
Her Three Songs from Quasimodo won awards from both the National Endowment for the Arts and the International Society for Contemporary Music.
In 2003 Zallman was a guest composer-in-residence at the Rocca di Mezzo Music Festival in the Abruzzi region of Italy.