This is exactly how relaxed you want a dog at your wedding to feel. This means you need to provide Ms Muttons or her friends the things she needs to be relaxed. It also means you need to avoid the things that make her really uncomfortable.
I did a wedding once where an extremely well-behaved shepherd did ring duty. Unfortunately, for both the dog and the musician, they had added a flute piece very close to the ring exchange. Poor pup put his paws over his ears and howled. Poor musician was in tears. Luckily, this happened during the rehearsal, so they were able to have a Friend of the Dog remove the puppela after the recessional and bring the puppela back in for his job.
It did mean the handler missed the wedding. But the dog had a much better time.
Tip: think carefully about the dog’s likes and dislikes before subjecting them to a wedding. If large crowds bother your dog, it’s not fair to invite them. If certain music irritates, you can’t do both. You need to take good care of your dog and not just consider your own needs. What’s important to you may or may not be important to your dog!