You could buy them an activity at the resort. Scuba or a shopping tour. No money, They most likely have all they need so skip the household items.

Check with the resort where you are staying. If they haven't already arranged it, order a champagne reception for them (champagne in an ice bucket and usually some flowers or snacks like strawberries for when they check-in) and fancy breakfast the morning after the wedding. A great way to treat someone who has everything and can afford more than you can at a destination wedding.

I agree with the resaurant gift card or maybe tickets to a show idea. I wouldn't give cash.

A gift card to a nice restaurant you are sure they'd use.

She is young (about 50) and this is her third marriage. Destination wedding but they are paying for our whole family to go attend. They are very active, travel a lot (careers in sales) and have a relatively modest home in the Northeast. Not really into fancy China patterns, that sort of thing. I don't think they are registering.

Need ideas on what to give them as a wedding gift, and how much to dedicate to this? For my brother's first marriage I gave $250 cash but not sure if cash would be appropriate for a MIL/+new FIL? Any other ideas?