Steve and George:

I believe this thread is an excellent opportunity to enrich George's web site with the experience of RC pilots that have been involved with training of children regarding the best methods of teaching and the equipment more suitable for children of different ages and gender.
Most instructors at most of the RC clubs will recommend a four channel traditional glow powered trainer; however, I doubt that package suits the maturity level and understanding capacity of very young trainees.
I am inclined to sacrifice some of the advantages of a regular traditional trainer in order to provide a training that can be safer and more enjoyable for a very young trainee and the members of the club sharing the field.

As I wrote above, I agree with the choice of an electric midsize sailplane for an eight years old trainee.
He will be able to learn maneuvers, proper approach and pinpoint landing on grass, in calmed or windy conditions, using four standard controls, during the time the model last.
That will produce minimum hazard for the pilot, properties and spectators, because of the weight and speed of such a model.

With that flying time under his experienced wings, it would be a better time for the student to jump into the challenges of a regular trainer flown at a RC club.
I understand that supposes extra expenses, as I believe that there is no price for step by step training and flight safety.

Regards!