The LA Times has just run an article. I can see it says Erin is a sweet, sweet soul, but that's all as it's behind a paywall.
http://www.latimes.com/local/lanow/la-me-ln-erin-corwin-missing-joshua-tree-20140706-story.html
More from this article:
Heavilin told WBIR-TV in Tennessee last week the family hopes Corwin simply lost her way in the park. "She's just really timid and she has a terrible sense of direction,” Heavilin said. “We were all scared for her to travel home on her own because she had to go through airports by herself and it can be kind of overwhelming if you don't have a good sense of direction.”
So, now we learn that Erin allegedly didn't have a good sense of direction
Most Sincerely, MoeJoey