The other possibility for a tear-jerk conversation re: Johanna is that Jim Beckett is part of the conversation. Close as he and Kate are, I would be surprised if there wasn't a good father-daughter conversation about the topic of her mother and the wedding.
I know from personal experience that for those of us who lost a parent young (via death, not divorce), planning a wedding becomes a major occasion for opening up the reminiscences. In my own case, after about an hour at the reception, I lost count of how many guests mentioned either my Dad or DH's dad when they came up to congratulate us. It was very kind, really. (Of course, I'm the youngest daughter, so there was history. My dad never could hold his liquor, and he got teary-eyed when he drank. He was famous for getting caught crying at weddings; it was something that people remembered fondly about him. Everyone but my Mom, of course -- she was always mortified.)
