I would think that the middle school years would be the most appropriate for this particular work by Lowry. Much of her writing is aimed at this group, but I think that the issues brought up in this work make it more appropriate for children in grades 6-8. The issue of child abuse is one where some level of maturation in the reader is needed. At the same time, Lowry's playing with the "insider/ outsider" dynamic is highly relevant to the middle school child, who struggles, for the most part, with this dynamic on an almost daily basis. The mere definition of "normal" and the practices of exclusion based on this designation is something that seems to be quite appropriate for the middle school aged child, psychologically and cognitively becoming more aware of differences within individuals and within themselves. I think that these issues make the book something that can be read and appreciated by children in grades 6-8.