I just returned from a week in the Galapagos with my wife, who is a non-diver and gets sea sick. This was a tough decision as it it a very expensive trip and you get no breaks for non-divers. But this is a once in a lifetime trip to a spot few ever get to go, divers or not. So we decided she should go.
It would help to know what liveaboard you are on. We were on the Aggressor which is like a floating hotel. She worked very hard to get over her seasickness and in the end did fine- a bigger boat did help. As far as surreal and romantic, well I guess it could be. But when you are either diving or taking land tours every day, bed time comes early, especially when you start each day at 6:30 am (you are on a very tight schedule in the Galapagos), so there was not much nightlife. During the day, especially 4 dive days, we saw each other for breakfast and lunch, quickly during the SI's, and then really at dinner. She really had to amuse herself, but did so since the crew was great and friendly, and we did have a few divers sit out dives here and there that she could visit with.
Was it worth it? Yes in that she got to go somewhere very unique and exciting (we spent some extra days in Ecuador too). But the time on the boat was a lot of time watching the rest of us dive, or talk about diving, or looking at pictures of the dives, or messing with dive gear and cameras. If it wasn't to the Galapagos, I doubt she would have had a great time.