Sandra, check out David Lodge's Souls and Bodies, one of the most Catholic of his novels, which, although it starts out in 1952, follows several couples through their marriages over the next 25 years and encapsulates many of the changes the church went through after Vatican II. It may give you some insight as to how your characters would have been advised to proceed if they wanted to maintain their standing within the Catholic church.
I do remember hearing of two couples of different religions marrying when I was a pre-teen in Brooklyn (that would have been around 1965-66.), wherein the Jewish bride-to-be was told she would have to renounce her faith and take lengthy religious instruction before their banns could be announced, and in the other, the groom of some Protestant denomination had to undergo some instruction, and that couple was married in both her church and his on successive Saturdays. They later mentioned that the Catholic church did not recognize the second ceremony as anything more than a personal desire on the groom's part. I was only 12 or 13 then, so this was all hearsay that I never had the need to validate, but it may be helpful to you.
The Lodge book, by the way, I do not consider one of his best because the dogma overrides the narrative, but that too may prove helpful to you.
With all the research you are putting in, I feel you are going to shine in November. I haven't even begun to think about what I'm going to work on.
Thanks Michael - I'll certainly check out David Lodge.
At the end of the 1960s the telephonist where I worked married an American Catholic GI. Because I saw her daily I came in for a lot of the day to day progress of the preparations, among which was her conversion to Roman Catholicism – essential, as far as I understood and/or remember it. I also knew that the reason one could not have a civil marriage later than midday was because registrars were required to attend Catholic weddings in order to perform the whole ceremony again – before they couple signed the register.
I'm not wanting / needing to know too much about the ins & outs, just to prevent my best-selling novel being hurled across the room in disgust because of blatant untruths/lack of research.