Having lived in Knothole for some time during the First Robotnik War, Elizabeth and her family were eventually captured by Dr. Robotnik as part of Operation: EndGame. Robotnik had managed to locate Knothole due to detecting Horatio's Dream Watcher device, and took Elizabeth and the children as hostages, forcing Horatio to assist him. This led to Sally Acorn's near death and Sonic the Hedgehog being framed for her murder. Fortunately, Horatio was able to conceal the fact of Sally's survival, and Robotnik's subsequent demise saw the Quacks freed and reunited with their husband and father. (StH: #49, #50, CSE)
Elizabeth Quack is described as being "plucky and upbeat." (CSE) She loves her children and her husband, whom she calls by his middle name of Quentin.