Up until this point, Jem and Scout acted the same age, despite Jem being four years older. We believe that Mrs. Dubose represented a gateway that Jem and Scout must must pass through in order to start growing up and develop the bravery and independence that they will need while their father is representing a black man. Jem is scared of Mrs. Dubose, and doesn’t want to read to her, but he must because it is what’s right. In facing his fears, he took another step in life, and gained a friend, even if he might not have realized it at the time. The flower that Mrs. Dubose gave him at the end symbolized a protector, and the holder is the one being protected, showing that even with the rough road ahead, Jem has someone to look after him.
Scout is going into a situation that leaves her against the school, as nobody thinks the man her father is defending is innocent. The drugs that Mrs. Dubose was hooked on represent the claws that Scout will have to break free of to see past her classmates and discover that all are equal.