Maria Bonasera was the daughter of Amerigo Bonasera.
Bonasera's only child and the goddaughter of Carmela Corleone, she was raised in the 'American fashion', given freedom, yet also taught never to dishonour her family. As she got older, Maria began to stay out late, and worry her father by hanging around with the loutish Kevin Moonan. Bonasera did not protest, which he later regretted, as one night, Moonan took her out with his friend Jerry Wagner, got Maria drunk and tried to take advantage of her. Maria resisted, and she was instead beaten, receiving numerous injuries including a broken jaw. Devastated, Bonasera took his case to Don Corleone.
Corleone sent his hired men, led by Paulie Gatto, to deal with Moonan and Wagner, who were beaten within an inch of their lives and thrown in to open graves.