Ah seekeerz, I feel for you, any parent would want to be at their daughters big day, of course you are gutted, I'd be gutted too. She may come round to your idea, if not, you'll just have to keep schtum really, else you may harm your relationship.
A few years ago my friend was determined to get married in secret with just me and my husband as witnesses, we were very uncomfortable with it as we know both families well, I convinced her to change her mind a couple of weeks before the big day, she's glad she did as her dad got seriously ill a couple of years after with a terminal illness.