This is certainly a situation where a PLB would have made all the difference. But then if you don't plan well enough to bring more water than that to Death Valley in August, you probably don't own a PLB. And if you did have the water and the PLB, you are probably the kind of person who wouldn't try an offroad trip to Death Valley in August with a young child.

Not being snarky here, and I do feel for the mom. Thinking of that little kid drying out gets to me.