I agree with @hiram.k.hackenbacker here completely.
We’ve had gigs in the past where the venue has stipulated their regulations on us pre event and post agreeing with bride/groom, one venue insisted we set up before 11am and then leave until we play at 9!! That didn’t happen as they wouldn’t guarantee the safety of our gear 🤷🏻♂️
Your contract is with the bride, the venue has moved the goal posts, she should be involved in sorting this.
We had a party several years ago with a sound limiter and the crowd tripped it singing along. It does happen.
Good luck sorting it.