Hard to say what was going through her head. After changing a tire in the desert heat and leaving in such a hurry that she left the tire and water behind, frustration and anxiety (maybe anger) come to mind. Who knows. . . Suffice to say she maybe realized she was in over her head. At this point I'd be looking to turn around, but that would disappoint the kid so she pressed on.

I've used a GPS long enough to realize that they are very fallible (not infallible). For a trip like this I'd pre-flight by comparing the GPS maps to GoogleEarth. Adds just a bit of reality to the situation.

Stay on paved roads. Carry lots of water. I have 3 gallons in the truck now and I'll be on I-5 for my entire trip.