Stella's TEDx Talk:
The Guardian's report of the sad news with a selection of touching reactions on Twitter is here.
Stella's letter to her 80 year old self, reproduced on the ABC Drum web site, begins this way (and you can read the whole text via the link above.)
Dear 80-year-old me,
Eighty, hey? Eighty.
Eighty is a long way from where I write to you now. Fifty years, in fact.
To be honest, I've never thought a great deal about you, 80-year-old Stell. I tend not to think about living to some grand old age. Then again, I don't think about dying either. I suppose you do; you're 80. You've done a lot of things. Seen a lot of things. You almost certainly have a hover-chair by now. When I was seven and watched an episode of Beyond 2000 that featured a floating armchair, I thought we'd definitely have one of those by 15, at the latest. As we both now know, the 21st century has been nothing if not a tremendous lie.
Bummer.