The most basic advice for when you think you are lost; Sit down!
might have made a difference. And if possible get out of the rain, so you can think without your head being hammered.
If as soon as she realised she wasn't sure which way the trail was, she had started shouting (if she had no whistle), that would probably have been enough.
But no one should ever be without a whistle. People have fallen in a ditch in towns and been stuck there for days because it was too noisy for a shout to be heard.
The other thread on this has degenerated into people joking about this womans death, so hopefully it won't be merged with this one. And ideally deleted.
qjs