While you are waiting, Owlswung for replies from people, a number of whom haven't been logged on, can I just ask what you mean when you say Charlie Gard will be in Summerlands having what happened to him explained? In what sense will this poor child be in any way able to understand anything more than here, and what is being explained?
What goes to the Summerlands is the persons 'Spirit' - what makes them what they are that is not physical.
I do not have your way with words so this explantion will probably entail a to-and-fro in order for me to put over what I mean.
Charlie's Spirit will be fully aware of everything that Charlie was in life - his physical age will be no barrier to his understanding of what transpired between his birth and his death. In the Summerlands there will be others who will be, as he will be, awaiting the time of their re-birth who will cover the entire spectrum of human existance and experience.
Please, if this does not make sense to you, let me know in what way I need to clarify my vision of what the Summerlands represents to me personally - I cannot, as I have tried to explain before, speak for anyone else.
Ther basics are the same for all who believe in the Summerlands but the details tend to vary as, as with the Heaven of the Christians, exactly what is there and what happens there are matters of pure faith and speculation.