If you look at prior posts in this section, you'll find a bunch of posts about kids' packs. Steadman appears to have found a good one!

Trying to find a day pack for a pre-school child that has a hip belt (important to take pressure off the shoulders) and doesn't hang down below his crotch is not easy! I won't be looking for another kids' pack until the 11-year-old outgrows his Deuter Fox 30, since the younger kids have hand-me-downs to grow into. The one the six-year-old uses (Granite Gear Sidekick) was unfortunately discontinued several years ago.

For a slightly older child able to carry more weight, the REI Comet and Deuter Fox 30 are both good, although heavier than I'd like.