I am the more liberal in the family, and I think I'd be frowned upon by my brothers if they know I am here on this site. But they'd still accept me, and I guess will just mention to be careful. Same with my other sisters.
As for my dad, he'll probably be happy that I am out and looking for a husband. He's been asking when he'd walk me down the aisle.
My mom? She's probably fervently praying to God in heaven to send her unmarried siblings the love of our life and probably happy that I am taking the first step to finding that person. :)
If I became engaged to someone from this site, I think that I would be proud to let them know that we met on a Catholic dating site. I don't think that they would care much if I met my wife on match.com since half of my family is not practicing Catholic and is divorced :(