This is one of the hardest things grief asks of us when someone we love dies. I am lucky that my mother and I had been doing death cleaning for 3 years before she died, so I didn't have to make all the decisions by myself. But I remember one day sitting with an open box at my feet and staring into space holding a broken suncatcher and a single glove Mama had knitted that had no mate. Hank looked up and said, "Babe. What's wrong?" I burst into tears because I couldn't make the decision to throw these two obviously worthless things away. They were hers. He gently said, "Put it all away for now. Give yourself time. You don't have to do this now."
It took me more than a year to deal with all of it, and I still haven't gone through all the boxes of her papers. There are still things I am hanging on to that I know one day I will let go of, but I'm not ready yet.
The moral of this story is that it takes time and there is no timeline.