Respuesta :
Jem ages from 10 to 13 over the course of To Kill a Mockingbird, a period of great change in any child's life. Jem is no exception to this rule. Interestingly, the changes he undergoes are seen from the point-of-view of a younger sister, which gives a unique perspective on his growth.
He ages from 10-13 but mostly he was at age 12 for most of the book if I remember correctly