I'm sure everyone with elderly hoarders in their family-tree knows this, but I'll repeat it again here...
When the that sad time comes, GO THROUGH EVERYTHING. Every pocket, every drawer, every cardboard box, every envelope, every shoe & slipper, every sugar canister, every coffee-cup and so on. Do NOT assume that because junk is on the top, that it's junk all the way to the bottom. As some up-thread have mentioned, Hoarders can be afraid of losing their stuff and will often secret away valuables in odd places... like pockets, in little gift-jewelry boxes, taped to the back of dresser-drawers, *inside* mattresses and pillows... you get the idea.
agnes!
When the that sad time comes, GO THROUGH EVERYTHING. Every pocket, every drawer, every cardboard box, every envelope, every shoe & slipper, every sugar canister, every coffee-cup and so on. Do NOT assume that because junk is on the top, that it's junk all the way to the bottom. As some up-thread have mentioned, Hoarders can be afraid of losing their stuff and will often secret away valuables in odd places... like pockets, in little gift-jewelry boxes, taped to the back of dresser-drawers, *inside* mattresses and pillows... you get the idea.
agnes!
Can you imagine? The house is a TOTAL mess, the sink is loaded with clean dishes and she can barely get to the scrubbers and the dish soap and she's bothered by stickiness.
and it was taken to the dump!! When we found out, our stomachs dropped to the floor.. 

I have known may folks that did not have a firm grasp on the "should it stay or should it go" answer. It is very common and frustrating when the answer is obvious to so many others. I hope you are blessed to have a loved one that can support you if needed.