When I was in the same situation in summer to collect the money for her birthday gift and had asked her what she would like, she had no idea. So this time I didn't ask long and decided to just give the money to her (young married couples always need money anyway) and only would put it in a special box or something that had to look fancy (because it was a wedding gift) and was not so very expensive (because I wanted to give her as much money as possible and spend the least amount of it).
So I went to a special place and bought a hollow body shaped like a lighthouse (approx. 4 Euro) and a small wooden box (I think it was 2 Euro) and some decoration sand.
I cut a shoe box open at 2 sides, took a lot of old newspaper together with wallpaper paste and created a rock, painted the lighthouse and the box and put it together.
Finally I cut brown paper in a boat shape to have people sign it as a card and made a flag that had the wedding blessing on it.
That's how it turned out: