Dr. Zimmerman is a Diplomate in Clinical Psychology and a Fellow of the American Psychological Association. She is the author of many professional publications and papers on child development, and is the senior author of the widely used Preschool Language Scale (PLS). Dr. Zimmerman met her PLS co-authors (Violette Steiner and Roberta Pond) while visiting the early Head Start programs to report innovations in those programs.
Dr. Zimmerman is the co-author of two books about the Wechsler Scales (Clinical Interpretation of the WISC  and Clinical Interpretation of the WAIS ). She has conducted longitudinal research of children raised in alternate life styles and screening children for later problems in schools.
Dr. Zimmerman has been an avid birder and has travelled widely throughout the world (in Europe, Central and South America, Africa, Australia, and the Arctic!) with leading ornithologists. She has served as president of a local Audubon Society and also as a board member of a long-established bird study club.