Daisy Zachary McGuire grew up helping her dentist father, at his practice, where she pulled her first tooth at age six. Eventually, the North Carolina State Board of Dental Examiners required McGuire to go to dental school or she would have to quit practicing. McGuire graduated with honors from Southern Dental College in 1908 as the only woman in her class. All of McGuire's children became dentists, and most of her grandchildren also became dentists, with McGuires still practicing in the North Carolina area.