Just beacause she asked you to Maid of Honour, doesn't make it an invitation to CD. It could be something as simple as she want's you to share in her special day by playing an important part. I think that the invitation shows you how much she loves you as a brother.
I'd excercise caution on the cding part unless she specifically asks you if you go along with it. Don't push it too far. You may end up spoiling her day.
If I'm wrong about this then I apologise
