I'd pull back the Fowl series for a couple years. It's got complicated issues involving consent, imprisonment, and violence in those situations that might not be very easy to contextually for someone that young. I was advanced for a reader at that age, but I found a lot of enjoyment in the Redwall series. It had great worldbuilding and an interesting setting for a kid just about that age. They might be a little difficult to get them to actually sit down and read though, as they are definitely larger books for children.