Kallir was known for her performances of Mozart works, both in solo recital and in duets with her husband, pianist Claude Frank. She also played in many chamber-music recitals, with such musicians as Pinchas Zukerman, Yo-Yo Ma, and Richard Stoltzman.
Born in Prague in 1931, Kallir made her performance debut at age four. After moving to New York in 1940, she studied piano with Isabelle Vengerova and Herman de Grab and in 1949 participated in an evening of concertos at Carnegie Hall, performing the Schumann Concerto and a then-new work by Alan Hovhaness that included playing the piano strings with a timpani stick.
Kallir met her husband in 1947 at Tanglewood. Their daughter is the violinist Pamela Frank.