It's such a commonly used word when it comes to children. 'You're such a naughty boy/girl' and 'that was a really naughty thing to do'. I hear it all the time.
But the truth is, I hate the word with a passion! And I don't think it's an appropriate word to use with children. It's not constructive and it doesn't give them any feedback about what they are actually doing wrong.
Children need to know why their behaviour is inappropriate and given gentle guidance to help them do the right thing. They don't need a smack on the bum and to be told they're 'naughty'. That doesn't teach them anything. In fact, they are more likely to imitate that behaviour and to go around repeating 'naughty. naughty'. Which doesn't do anything but annoy the parents!!
And yes, I have been known to use the word 'naughty' at times. Usually in the case of extreme frustration, when I can't think of anything better to say. Which just goes to prove my point that the word 'naughty' has very little meaning.