I found it emotionally wrenching to get rid off my parents' "stuff" -- but that was my problem, not theirs! They weren't wealthy, but they had a wide range of hobbies and interests. So I had to deal with camping gear, yarn, wood for carving, gardening equipment, sheet music -- the leftovers from two full and interesting lives.
I also found evidence of the depression-era mentality -- screws and buttons and lots of things that might be reused were saved. It was a large, painful and difficult job for me to sort, sell or give away the contents of their house. But I would never say they should have limited their interests or activities simply to spare me that task.
I don't want to criticize your friend, especially if she is grieving, but I would wonder about the emotional maturity of anyone who can't handle disposing of parents' possessions. Such things are a normal, albeit difficult, part of adult life.