Diana's greatest contribution to the world and the human condition was to denounce prejudice and encourage tolerance towards the very ill, particularly those who were suffering from AIDS. Decades later, this might not be so well appreciated, nor the enormous impact she had on the public consciousness at the time. In this, Diana was remarkable, and she deserves honour and praise for her unfailing understanding and pity.
I've said this before and I'll say it again: which other royal, from anywhere, has embraced the world and it's alarms as comprehensibly as Diana did?
How many other royals, from anywhere, have you heard of who would willingly grab the hand of a leper, or someone dying of AIDS?
Whether she was a good Mum Wife, Princess, etc. isn't really the point. When the chips were down, the lady had the courage of her convictions.