I’ll sing you a song of the long ago - Seven shine the shiners, oh! What did the Seven do way back when? Why, they wove the Charter then! Five for th… - Garth Nix

I don't believe authors need to keep any specific values or ideas in mind while they are writing for children, but I do think authors need to be aware of their audience, and of the effect their work may have. So if they want to address particularly sensitive topics or taboos, they have to do so consciously and carefully. This is very different to toeing a particular moral line or leaving things out. Certainly I don't think good always has to triumph over evil; it depends on the story and the aims of the book. For example, I could envisage telling a story where the inaction of people leads to the triumph of evil. But I would include the hope that this would lead to the people involved doing better next time. Is that story then really about the triumph of evil, or is it about the awakening of opposition to evil?

"You are a weak reed, Recruit Green!" Helve shouted. "Weak reeds make for badly woven baskets! This platoon will not be a badly woven basket!"

Five Great Charters knit the land
together linked hand and hand.
One in the people who wear the crown
Two in the folk who keep the Dead down
Three and Five became stone and mortar
Four sees all in frozen water.