She didn’t take her husband’s name.
Elizabeth’s father, George VI, was born into the House of Saxe-Coburg and Gotha, but during World War I the family name was changed to Windsor amid anti-German sentiment. Similarly, her husband Prince Philip dropped his father’s Germanic surname, Schleswig-Holstein-Sonderburg-Glücksburg, and adopted that of his maternal grandparents, Mountbatten, during their engagement.