I meant nude kids or adults, in a natural context - eg Amazonian tribes in The Mission, or that shot in Clash of the Titans where naked mother and son walk along a beach hand in hand (shot from behind).
Anyway, yes Walkabout is one of my favourites. Nic Roeg, the director, is also one of my favourites (he also made Performance, The Man Who Fell to Earth, and Don't Look Now). From what I understand, there was nothing remotely untoward about the shoot of Walkabout (it isn't one of those films one hears posthumous behind the scenes horror stories about, unlike, say, Last Tango in Paris), though I don't think it could be made today.
Like you, I'm used to 16 being the age of consent, though goodness knows, I can't understand why the UK government think you're old enough to have sex but not old enough to vote. Madness.