Looks like you're off to a pretty good start.

I do have some suggestions as to gear selection that I'll share with you.

Eliminate the firestarters and exchange them with a container of Vaseline impregnated cotton balls. The smallest spark will ignite these "tinder" balls. They're extremely inexpensive and work very well. Add a butane lighter as well. I'm a fan of duplication except when it comes to fire and that I triplicate!

Tent? Perhaps get a good lightweight siltarp and learn to make a variety of shelters out of it? Good ponchos will give you the same ability and provide raingear as well. You can attach two ponchos and make a very comfortable tent quickly. Open and close the hood for ventilation. I've spent many rainy nights in Washington and Germany in a poncho tent and have been very comfy.

I think the MREs have a purpose and that's for cold or quick camp meals. Freeze dried is lighter but you need hot water for most of the entrees. That means fire and that means smoke and light -- which if you're trying to hide could be problematic. You can find lots of quick prep food at your grocery much cheaper than commercial "prepper" food. Consider high calorie & fat food like peanuts.

Water: you'll need a lot more than the bottle you show can hold. Consider a single walled steel bottle: you can boil directly in the bottle. Also, maybe some bag "bottles" like the flat Nalgene or Platypus ones. There are also hose & nipple kits that convert these bottles to hydration inserts. Well worth the money.

I have a small Trangia alcohol stove that uses gasoline alcohol (methanol only!) additive. Smokeless and very compact. You can also easily make an alcohol stove from a two soda cans and a pocket knife. I also have a twig burning stove as mentioned above -- endless fuel.

Extra socks! Keep them in a water proof bag. They're worth their weight in gold when your feet are wet and tired. Also, good boots that are well broken in and waterproofed!

I think in order to cover that distance on foot you'll have to have some sort of wheeled cart. I like the game cart idea but have seen several others on websites of people walking around the world. Certainly your child won't cover that distance easily on foot. Also, make certain your pack truly fits or you'll be miserable in a couple miles.

Finally learn and practice skills! Making improvised shelters, fire, traps, the alcohol stove I mentioned, and so many others. Skills and knowledge are key and are more important than gear.