We- at GS camp in Iowa- were told it was written by a girl in Holland who was in a wheel chair and confined to the top floor of her house. I'm pretty sure the sick kid/wheel chair story is a bunch of bunk made up to inspire solemnity in hyperactive kids still crazy from the day's adventures, and then warped slighty each time it made it's way to a new camp. For me, personally, the fact that it is such a strong Girl Scout/Guide tradition and that so many camp people are tied together by it is sentimental enough.

We only sang the first two verses, sometimes with harmony, sometimes without. We never hummed a third verse.

I'm afraid the message Jen M quoted (four years ago!!) is all the origin we're going to get with this one.