Daughter's Questions: Creation Ex Nihilo

In our experience, everything that is made, is made from something, or by some means. This leads quickly to a difficult question which my daughter asked recently: when God made the universe, how did He make it? what did He make it from?

An interesting but (due to my daughter's age) difficult discussion followed about the distinction between "made from nothing" and "not made out of anything".

How would you answer this one?