Any ideas for a wedding gift?

So my sister is getting married on Wednesday morning (I know, strange time for a wedding), and I still have no clue what to get her. She’s been with this guy for over ten years, and they’ve lived together for the majority of that time. She owns her home, and does not need anything along those lines. I thought of a gift certificate to a favorite restaurant, but she’s been on a really strict diet lately, so I’d rather come up with something else.

I would appreciate any ideas…