It seems that "Boys will be boys" is a well established idiom and, according to Cambridge Idioms Dictionary, 2nd ed, as it is written on The Free Dictionary, it is "something that you say which means it is not surprising when boys or men behave in a noisy, rude, or unpleasant way."
So I began to wonder if "Girls will be girls" is a phrase that begins to take on an idiomatic meaning in English. Is it so?
If yes, in what circumstances do Americans or Brits use it? And, what do they want to say when they use it?