I’ve been known to tell “blonde jokes”, but no; too soon. 
I still like the idea of the little girl springing from behind the pole and calmly raining bullets on them. Then, when some of them manage to get to their cars and speed away, she runs after them with like dude from Terminator 2.
If they made the “little girl” actually be a baby–extra points if she’s dolled up in pink and ruffles–then that would be the extra layer of absurdity that would ensure near universal funniness. In terms of irony, it would also lampoon the sexist suggestion that little girls are weak and cowardly.
People are reading far more into the joke than is there. There are no good guys or bad guys because the butt of the joke was* the English language*. They were saying “where is the little girl”, implying that there was a little girl missing but in the end revealing that they really were searching for someone who would react strongly, matching the common figure of speech " crying like a little girl." It is a pune, or play on words, like “the leopard can’t change his shorts.”
I believe that if some of you reading this thread look up, you may still see the “whoosh” above you, because it was so high up it is in geosynchronous orbit.
“Where’s the little baby” would have worked just as fine for me.
For certain types of humor, absolutely.
Yeah. Absolutely nothing about the “humorousness” of his joke would have been changed by substituting “baby” for “girl.” Babies cry. “Cry like a baby” is every bit as common an expression as “cry like a little girl.” (629,000 Google results to 626,000). And that would have taken the misogynistic “insult a male by referring to him as a female” vibe out of it.