Adding to the list, some of the books I remember reading a long time ago...
The Secret Garden by Frances Burnett Call It Courage by Armstrong Sperry Around The World In 80 Days by Jules Verne James and the Giant Peach by Roald Dahl Charlotte's Web by E.B. White
St-Exupéry's The Little Prince. This is a particularly good choice because you can probably find it in Korean as well. [It has been translated into more languages than any other book, save the Bible.]
But, some of your suggestions are classics. I'm more interested in current books. Some titles sound new (modern?) I will seach for them. Thank you again.
Do you like horses at all? My daughter has enjoyed a series by an author named Lauren Brooke called the "Heartland" series. The stories are not too "juvenile" but the writing is probably good for a beginner.
But Charlotte's Web (even if it is an old one) is a good read. As much as I love The Secret Garden, the attempt to reproduce the Yorkshire accent will make it VERY diff
Some of these books suggested were about the same level as Holes or The Giver. My recommendation: Gathering Blue, by Lois Lowry. This book is basically a sequel to The Giver. It's absolutely wonderful just like its prequel.