Excellent idea. I think she could provide another interesting new element. Besides Vito Legacy's "hard-nails reporter" story, I would add her later on Sicily, when Vincent would be under the guidence of Don Luchesi and they make love and then Ms. Hamilton would declare her love to Vincent (little hard to show, but with the right ingrediants, could happen), creating with that way an interesting love triangle between Vincent-May-Grace, and when he becomes Don Corleone, he takes Grace Hamilton as his escort and tells he may actually marry her...

I will include her in the upcoming re-working of The Godfather Part III, retitled THE TRAGEDY OF MICHAEL CORLEONE.