Recommendation:
On the whole, I´d recommend the book to boys and girls from grade 8 to 10 as it is a nice detective story whose length and language is appropriate for both sexes of that age group. But if you are looking for suspense, you should go for another book because it is very obvious who murdered the old lady. Personally, I liked reading the book because it gives you an insight into living in New York City - both as a homeless person and as an affluent one. And yet, the book is pretty average and has no special message for the reader.