Mary Joestar

History
It is shown that Mary died in the fateful cart accident that Dario Brando "saves" her husband George Joestar I from. Mary's face is later seen in a picture in Jonathan's room. The night Danny dies, Jonathan is seen crying and looking at the picture, missing his mother. Years later, Jonathan studies the mechanics behind the stone mask, mentioning how the mask was originally obtained from his mother's travels.

When Dio Brando is revealed to have been poisoning George, a police inspector tells Speedwagon that Dario stole her wedding ring from her corpse and tried to sell it. He was arrested, but George told the inspector that he actually gave the ring to Dario, forgiving him for his theft.