Shortened form of "the fact that she was alive"

Solution 1:

"The rest of the world" is a pretty tired cliche. Why not just rewrite as "She succeeded in faking her death" or "She successfully faked her own death"?

Solution 2:

Hot Licks' suggestion happens to fit what I want, but it hasn't been posted as an answer, so I'll just post it myself:

After she faked her death, she kept her survival a secret from the rest of the world.

It does come with a few caveats. While my comment fell short in identifying the a potential problem when using 'survival', TrevorD's comment successfully identified a commonly understood definition of 'survival':

To me, the word 'survival' implies that she was involved in an incident that she may not have survived. But faking her death need not involve any such incident.

And as Sam notes in their answer:

"The rest of the world" is a pretty tired cliche.