I think I first read this story in a Reader's Digest "Drama in Real Life" article. And they said the same thing - quite a few people survived the crash, but everyone just sat around waiting to be rescued - none of them survived, in the end.

I suppose whether Koepcke did the "right" thing or not is probably undecidable; lots of people do the "right" thing and don't survive, lots do everything wrong and muddle through anyway. But she appears to have remained cool and made rational decisions, and in the end, she did survive.