"Dehydrated" is probably the wrong term. I bake the kale until the moisture is all gone, usually at 350 degrees for about 10 mins (but I continually check). I have done it at lower temperatures, though that obviously ups the cooking time. The result is the crispiest, flakiest bits of kale. Ds really enjoys the texture. The baking also seems to take the bitterness out of it.
If dehydrating allows the nutritional content to remain pretty in tact, then I imagine this process is decent too.
Let me know how you like the "kale chips". I haven't really known anyone else to make them, and I'm wondering how your kids like them.