Plan to have a low-key and pleasant time on Sunday. The goal should be that afterwards she goes away with good memories of it. Protect yourself emotionally and continue to keep expectations at a low.

I think it's good that she's interested in participating in a family event. Use that opportunity to be easy going, positive and the type of guy any woman would enjoy being around. I don't think that will be difficult for you! \:\)

There is no arriving, ever. It is all a continual becoming.