I do not think the children were 'on show'. We saw very little of them and their parents did nothing to push them forward.
I think the royal family as a whole and as individuals, did what they thought was for the best and consulted the children, For example, I noticed that while Viscount Severn, Prince Edward's 14 year old son, took part in the 'Vigil of Princes' with all late Queen's grandchildren, he did not march in any of the processions with the other older grandsons and his uncles and aunt. I would imagine that was the result of he and his parents discussing it with him and letting him decide where he wanted to be, and I saw nothing in the behaviour of the younger children to suggest that they did not want to be where they were. Obviously they looked solemn but at various times you saw them whispering to each other and smiling quite happily.