Thinking about this more, I figured i'd write down for some actual topics to cover. Trying to balance fun with content. Sometimes the most boring stuff is the most important.
-Shelter- already mentioned but one of the most fun and important things to do in the woods.
-Food- wild plants and other things. You can do fun stuff like berries and leeks and boiling water, and also gross stuff like grubs. Being able to eat gross stuff is a helpful skill. If the parents don't want them eating stuff they find in the woods, you could challenge them to go to each bring their own store-bought "gross" food. (oysters, anchovies, sardines, etc) and have a fun, buffet type game of who can eat the grossest stuff. It was a blast when I did it, but may be more of a boy thing.
-Fire- Fire is always fun and always needs practice. If you did it with them before, maybe show them different types. Long fire, upside down fire, dakota fire hole, etc. Getting them more time to practice is always good.
-You mentioned land nav, but how about movement techniques? Like safely crossing a stream/river, going up and down steep ravines, how to move through a thicket, etc.
-Signalling- Demo a signal fire and have them build one too. Have the group separate and signal each other from a long distance with mirrors, whistles, fires, etc.
-Traps- Snares, deadfalls, and other mechanisms always drew my attention as a kid. Seeing and building the different mechanisms was always really cool.
-Camp setup- How to place your shelter in relation to water sources, heating fire, cooking fire, sanitation, working area, bear/critter avoidance techniques
-Knife work- Basics like to cut away from you, batoning, how to break wood without a knife, etc.
Just a few ideas that could be fun. Curious to see what others come up with.