An apocalyptic novel with a very original premise

Supernova Era has a really interesting premise - what would happen if only those 13 years and under survived an apocalyptic event, in this case a supernova star showering earth with deadly radiation. It is well written and engaging. It is an idea and concept based book rather plot based, as many of the things that happen are completely unrealistic, e.g., 13 year olds learning to fly fighter and commercial planes in six months. There is also no discussion about what must be the inevitable high infant and early childhood mortality that would occur. It is a difficult book for parents to read as there are large numbers of children who die as a result of their own society’s bad decisions. However, this is the kind of book that will be fodder for long and interesting discussions. How would you prepare children for a world without adults?