That's an interesting perspective. I'm not sure whether I totally agree with it but it's certainly something to think about. I've gone the other way with my children (I have 5 kids ranging from 15 to 2 years old, all except the youngest backpack with me occasionally). I go very minimalist on their packs and I carry most of the gear. They usually only have their hammocks and their sleeping bags in their packs.

My questions/concerns with what you are saying are two-fold. I wish I could talk to a specialist in pediatric orthopedics.

1. Should kids carry a higher percentage of their weight than adults? My inclination is to say no because they are not scaled down adults, a higher percentage of their weight is organs as opposed to bones and muscle. So if anything I would think they should carry a lower percentage of their weight than I would.

2. Can you really transfer weight to a kids hips they way you do with an adult? As I look at my 6 and 10 year old and some of the younger scouts they seem to be built more like stick figures than like people. Their hips are not as wide compared to the rest of them. It sounds like your daughters hip belt worked well. That's not what seemed to be happening with the scouts I looked at. And I'm not sure it should. The hips develop their mass and strength comparatively late it seems to me. So my kid's packs are beltless or have a small belt that is just meant to keep the pack from flopping around.

Well I don't know the answer here. But it does appear that their is a variety of experience on the subject and more than one perspective.