When I look back on HP years after I read the books... Yes, there are some dark elements already in PS/SS. Harry loses his parents as a baby, gets neglected and abused by his aunt and uncle and bullied in school (even by his own cousin), one of his teachers has the man who killed his parents stuck on his head, and said teacher later basically gets burned to death. And that is just what I come up with on the top of my head right now. Yes, I suppose that the average 11-year-old (which is Harry's age in this story) is able to handle all this. But I would never give the book to any child, who is much younger than that. And as for the later half of the series, that is for teenagers and not for children.