Small town social life doesn't have anything to do with it. Mrs. Alito (based on this article) did not know Mary Jo personally. It's a leap to say that she was crying about someone she's never met who has a vague relationship with her husband's family.
I would not go as far to say she was crying because of it but it was just another thing she had knowlege of the devastation that Ted Kennedy has caused one family and now was trying to do to her own family.