Wow! Apple is with us! I always said that Puzo made it all fairly clear.
Apple, you are doing so very fine that I read your posts with real pleasure.
Only thing I have to add, since you begun quoting the novel, is that there was no kind of wow, obligation or promise on Michael's side when he proposed to her. She pronounced a very important thing: "I love you. I don't care." (About him being gangster etc.) And only after that he told her about his legitimate plans, just sharing thoughts, and adding carefully " If everything goes right..."