My wife and I have attended the SCI show regularly regularly recently. A few years ago, I had to buy her a membership she could get a show ticket (plus the cost of the show). Does anyone know of that is still a requirement or can I let it lapse?

Your wife does NOT need to be a member to attend the show. Just be sure you purchase her ticket at the time you purchase yours. You can do this online where there is a place on the registration form for your spouse.

My wife wouldn't miss the SCI show, and hasn't missed one in 16 years, except for when I became sick one week before the event and we had to cancel.