I know from having had a child, and from having been a child myself, that children will copy you. So, the best way to get them to read, is to read. The best way to get them to do anything is to do it yourself, and they will absolutely copy you. That way, you don't have to worry about what's supposedly age appropriate, a child will pick something up when the child is ready.
If there is no solution to the problem then don't waste time worrying about it. If there is a solution to the problem then don't waste time worrying about it.
When mortals are alive, they worry about death. When they're full, they worry about hunger. Theirs is the Great Uncertainty. But sages don't consider the past. And they don't worry about the future. Nor do they cling to the present. And from moment to moment they follow the Way.
So the best thing is to really work on yourself and opening your own heart and just letting all that stuff [worrying] go. And it is possible. It's sometimes takes a lot of time; it's not easy. And a lot of sitting with yourself and trying to work with your own heart.