I was recently asked; 'how do you keep the kids, particularly the six year old motivated'?
The two girls are awesome and love the outdoors. The six year old whinges a bit, but as long as you give her regular food and drink stops, she will get there in the end. The 8 year old, whilst not the fittest person in the world, has the stamina and is like a sponge with info on the flora and fauna. The two of them will always race you back to the car and win!
We always make sure there are 'rewards' along the bushwalk. A great view, swimming hole, waterfall, rock climb etc. We seldom tell them we are going bushwalking till the last minute, as plans can change, so this eliminated the disappointment aspect.
Their biggest achievement so far was Mt. Warning.