Zena executed numerous portrait commissions, primarily in sculpture, but also in drawing and painting, such as those of S. Jay Levey, whose wife founded the National Parkinson Foundation in tribute to him; Miami Beach Mayor Chuck Hall; and Rabbi Irving Lehrman. In addition to public and private commissions, she sought out ordinary people whose inner beauty she saw and highly accomplished people like Scott Nearing and Linus Pauling for her subjects. Other portrait busts in her studio archive include those of John F. Kennedy, Richard Nixon, Martin Luther King, Jr., and Mahatma Gandhi.h

Her portrait of Scott Nearing -- political science professor, economist, radical, and founder of the modern ecology movement -- is in the permanent collection of the National Portrait Gallery, Smithsonian Institution, Washington, D.C. Zena’s work is represented in other public art collections: The Wolfsonian and The Jewish Museum of Florida, Miami Beach; The Fellowship, Pennsylvania Academy of the Fine Arts, Philadelphia; and the Washington County Museum of Fine Arts, Hagerstown, Maryland.

Her Artists Speak for Peace archive belongs to the Swarthmore College Peace Collection, Swarthmore, PA.