Why did Coppola cast his daughter for Mary's role in The Godfather part III?

Francis Ford Coppola cast his daughter, Sofia Coppola, in the role of Mary Corleone in "The Godfather Part III" for both personal and practical reasons. He believed that Sofia could bring an authentic, fresh perspective to the character, and he wanted to work with her as an actress. Additionally, after other casting choices fell through, he felt a familial connection would help convey the emotional depth required for the role. Despite mixed reviews of her performance, Coppola's decision was rooted in a desire to blend family and filmmaking.