Remind your kids that this is a theory, not proven fact. Invite them to challenge it. For example, according to this theory, all changes are driven by natural forces alone as a result of survival of the fittest. But then an ecosystem would be in equilibrium with a few hundred species, not millions. The stunning variety does not fit the model well.
Also why then does evolution result in something so incredibly complex, such as electricity, with certain species not only generating it but storing it while something so incredibly simple such as the wheel is 100% human?