Children on long multi-day bushwalks?

I was recently planning my second bushwalk though the Cradle Mountain Overland track (in February), and in while doing so I was showing my nephew (aged 7) photos I took from my first trip, earlier this March. Since then, he's become adamant that he is coming along with me, which I thought might actually be fun. I've taken him on single day bushwalks in the blue mountains before which he's been able to handle, though he wasn't carrying anything, and the weather was mild.
My question to any other multi-day bushwalkers here though, is have you taken your children or younger family members on a long hike like Cradle before? More importantly, if so would you do it again? Also, what is the most weight you would recommend for a child who is still going though growth. I'm sure I'd have to end up carrying most of his equipment as well. Feel free to add anything else I should be asking, but haven't considered yet too.
I've tried to explain to him as best as I could that the location is remote - if he gets tired, theres no ending things early. He is a pretty tough kid (quite brave too), and he is surprisingly big for his age, but I'm not sure he understand the concepts of just how exhausted you can get, slogging your way uphill with a pack on your back. Still, I had read in the journal books in the huts along the way that children as young as him have done it too.. though they all do seem to be complaining a lot!
Just a few details worth mentioning: I'll probably be going with at least 3 of my other friends (none of whom have done a multi-day before), his mother is not going to be coming, and we're hoping to do it over 7 days (going to the Acropolis, but catching the ferry).
Thanks for any opinions!
My question to any other multi-day bushwalkers here though, is have you taken your children or younger family members on a long hike like Cradle before? More importantly, if so would you do it again? Also, what is the most weight you would recommend for a child who is still going though growth. I'm sure I'd have to end up carrying most of his equipment as well. Feel free to add anything else I should be asking, but haven't considered yet too.
I've tried to explain to him as best as I could that the location is remote - if he gets tired, theres no ending things early. He is a pretty tough kid (quite brave too), and he is surprisingly big for his age, but I'm not sure he understand the concepts of just how exhausted you can get, slogging your way uphill with a pack on your back. Still, I had read in the journal books in the huts along the way that children as young as him have done it too.. though they all do seem to be complaining a lot!
Just a few details worth mentioning: I'll probably be going with at least 3 of my other friends (none of whom have done a multi-day before), his mother is not going to be coming, and we're hoping to do it over 7 days (going to the Acropolis, but catching the ferry).
Thanks for any opinions!