If the nude children were in photos or paintings that were less than
life size, I'd probably go with ignoring it, as you suggest .  However,
since they are 'life-size' that could have more impact.

How about a discreet line somewhere, (not too bold; not too hidden) to
the effect that 'Parents may wish to explain to their children that
different cultures have different ideas about what clothing children
should wear.'

If you take a matter-of-fact but forthcoming approach you are less
likely to have upset parents or others.  And no one gets surprised,
which is usually when moral outrage pops up.

Lucy Skjelstad