In the interest of full disclosure I made exactly that sort of mistake 38 years ago when I got married.
I hired a soloist who sang at weddings in the Catholic Church all the time so I assumed that everything on her list was fine. Today I shudder at the thought of what I picked, but I didn’t know any better and if someone had said ‘that’s not appropriate’ I would have just said 'OK, I’ll choose something else." Today brides are unlikely to be that agreeable.
We didn’t have a Mass because my husband is not Catholic. My processional was “First Time Ever I Saw Your Face”. To this day I praise God that our church was small so that we didn’t get to the third verse because my mother would have passed out in the pew. I had never heard the whole song.
The signing of the register was “The Wedding Song”, you know, “He is now to be among you at the calling of your hearts…” OK, while I’m sure it’s about Jesus I would never pick that today because of the ambiguous nature of the lyrics but at the time it was the most popular ‘wedding’ piece going.
The recessional was Edith Piaf’s ‘L’hymne à l’amour’ – I suppose it compares to Etta’s “At Last”