Is the child correct when saying "the balloon is flying on my hand"?

I taught my child a lot of expressions to a point that he can create his own words.

Today he said "the balloon is flying on my hand" when he was holding a balloon by its neck and it was swaying back and forth when it was triggered by some wind.

I have never used the preposition "on" like that before, he must have chosen that preposition based on his own judgement and experience.

Is the child correct when saying "the balloon is flying on my hand" in this situation?