P.M.
My first husband was a fairly dark-skinned Middle Easterner, and I am a pale redhead. We drew many "looks" and a couple of comments over the years. Since I didn't feel I had done anything to be ashamed of, I would just give a sweet smile or a kind comment in return. People never knew what to do with that, so the subject would change. Sometimes they would blush.
In the future, if you hear someone say that "they believe" you shouldn't be married to this man, why not try smiling warmly and saying with enthusiasm, "Thank you for your opinion! I hear that you disagree with interracial marriage! And I obviously believe otherwise!" Be transparent and friendly; no ironic tone is necessary.
Watch what happens! And you daughter will be watching, too. I'll bet you can all smile about it later.
As for the woman who made the comment, that's done, so don't bring it up again unless she does. Let it go – it won't harm you unless you hang on to it.