Forming questions

Jon, 

there are several ways to ask questions in French. 

See attached link for simple questions such as this example.  

Asking yes/no questions in French with intonation, est-ce que, n'est-ce pas (French Questions)

Also, using subject-verb inversion (avez-vous) tends to be more formal than a statement framed as a question (vous avez faim ?) so the second is more likely for someone addressing children.