No? Then that proves she doesn't have one.
The fallacy in logic is when asked to “prove it” you simply retort “no, you disprove it”. The answer is neither side can empirically measure and prove or disprove the existence of God, therefore it is an article of faith for both camps.
This teacher is somehow getting off on intellectually bullying children on a philosophical point that has been argued by humans since the dawn of time. What a loser.