The problem with Rivka that it has a yiddish, even more than Hebrew or Old Testament vibe. It's not the same for Miriam or a bunch of other Hebrew names.
I think it's totally fine if, as a Catholic, you want to honor connections to Judaism, I think this name happens to be particularly unsuitable for this purpose.
- Formerly known as Murasaki-
Some thoughts and recipes
http://italianlaowaigirl.blogspot.com/
http://lagerusalemmecucinata.blogspot.com/