Only humans think death is evil. But it is nature. Evil exist's only in life. There is much good and evil alloted to each life.
Once upon a time, if you wanted to talk about the notion of child abandonment, of a mother not being a good mother, that's built into the mother who sends the babes into the woods, and they use the bits of bread or stones to come home again.
If fantasy is done well, it has both serious content in a literary fashion and is a really good read as well - and children and young adults won't suffer anything else.