Only three players completed boxed set - Doris Hart, Margaret Court and Martina Navratilova.
Honorable mention: If player wins all 4 majors, olympic gold and year-end tournament in same year, it’s called super slam. In 1988, Steffi Graf achived a non-calendar year super slam. In 2021, Diede de Groot achived this feat in women’s wheelchair singles.
Hingis actually was a game away on her own serve from getting the “Boxes Set”. She barely lost the 1999 French Open to Graf