A very interesting post. I didn't know children could live on their own in the sims. You seem to be doing great and have figured out a lot.
One question : why store food in the jungle adventure table and not in a fridge to keep it fresh for longer? There are off the grid fridges if that is what is stopping you. You can easily drag the food in and out of the fridge. I assume kids can add ice to the off the grid fridge, never tested it. Another option would be the food display from get to work, but I don't know if that works off grid.