Take a polaroid

Use her tactics: whatever you do, do make it appear you are doing it for her, or it's really she who wants you to do it

And by the way, do exactly everything you would do after 10 years of marriage. Divorcing after having had children is not good behaviour.

Be yourself. Don't be a French poodle

She married a photographer. It's also your trip not just hers!

(Excess number of due to the inevitable serious rebuking comments, although behind irony there can be a serious thought).