This is uh... hilarious... well, at least since the kid was smart enough here and nothing bad happened.
Of course you might say that Alexa just gave an answer similar to what the kid would have gotten looking the same up in a search engine.
It does raise specific questions though - for instance, it's been shown that a "robot" interacting with human voice was seen as more "human" to people, eliciting emotions and likely to be more trusted too. That would be especially true for kids.