bags- you grow in strength from post to post - respect!
I got married in a register office and my charming Mil was happy to come, but she would not have come if we had been married in a catholic church. As I had been an atheist from the age of 12, that was not likely to happen, but I nearly insisted on it just to spite her. It gave me a good insight into how some people think.
My daughter got married in church because she adores her future MIL, who had accepted her and her four children with open arms, and who was so thrilled to have a 'proper' marriage to attend. Both her own daughters had married abroad and she was unable to attend, although they graciously allowed their parents to pay for lavish receptions on their return home. My daughter said she would have been happily married in a tent, and 17 years later they are still deeply in love and very happy. Her own son married in church this summer, again to please his wife's family, who have a long connection with the local church. I think kindness for others is more important sometimes than principles.
I was very happy to attend both weddings and see such radiant happiness - I wasn't asked for advice, but if I had been I would have said they must do whatever made the most people happy. No christenings though, for any of my children, gc and great-gc and no religious services at the funerals of my mother, sister and brother. If anybody suggested getting in a cleric to mouth platitudes at my funeral, I would come back and haunt them.