It all depends on the disease process they have going on, if any. You are right though. I've known some old people who just dropped dead out of nowhere, some in their sleep, one real old lady while driving her car and stopped at a stop sign. Just stopped and car or her just never moved again. With the cancer that RGB had going on and her age, it's quite unlikely she was one of those who just went from being active to dropping like a fly. If she did conduct a wedding, it was more likely she just showed up and was more of like making a cameo appearance than actually conducting the ceremony.