It sucks to talk about and it's the last thing you want to be reminded of while you're supposed to be having fun on vacation, but after my father passed away we were told to bring a copy of his death certificate and we could get a prorated refund for the parts of his leftover ticket that were never used. Seemed a little drastic for the situation, but I guess without proof anybody could gamble with karma whenever they wanted in an attempt to be refunded. Personally, I don't think they will give you any trouble about the UTH tour, but I think it would definitely be beneficial to have if you wanted to pursue a full refund on that unused Annual Pass.
I hope your visit is a nice distraction and break from real life. I'm sorry for your loss. Hang in there.