There doesn't have to be anything more to this story than what's been stated. For one thing, she had natural water. There are streams and seeps all over Zion. From the New York Times:
...she injured her head on a tree with a blow so disorienting that she could not seek help or stray far. But she survived by staying near water until Sunday, when help found her.
Also she was an experienced hiker who presumably was properly dressed for the temperatures. You won't die of starvation in 12 days.
From the original article:
When Courtier was found, she was covered in bruises and had lost a lot of weight. She is now recovering in a hospital.
This is not a story of someone who spent 10 days in Vegas pretending to be lost.