No doubt It's one of the many weakest moments in the movie.
Kay dreaded him but she says, "I still love you, Michael, I always will." her horror

Michael spent a lot of time thinking of Kay even as he got married in Sicily Still loved her, his horror

She was deplorable too Abortion scene She didn't ask him to "forgive" her

She never understood nor supportive that he was a top Mafia boss, trying to become a "legitimate" businessman

1. She knew about the band leader's brains or his signature
2. She knew he was Mafia when she married him
3. Connie told her how many men were murdered along with Carlo
4. Happily enjoyed the unholy and evil spoils
5. Legitimacy was blood money laundering
6. When her bedroom was shot up suddenly dawned on her this Sicilian thing must all end

Hypocrite! If there was no shooting she would have continued enjoying the rich and powerful life