Mrs. Dubose has fully recovered from her morphine addiction. While at first Scout and Jem's visits were regulated by the alarm clock, by the last week "the alarm clock had ceased sounding, but Mrs. Dubose would release us with, 'That'll do,' so late in the afternoon." Even though this episode is incredibly difficult for the children due to Mrs. Dubose abuse and racist remarks, it is important for their education and maturation. In order to grow, Atticus knows they must witness true courage, which is what Mrs. Dubose represents. Even though she is, for all intents and purposes, a hateful old woman, her example is still one to follow.
Jem and Scout's visits were prompted by Jem's destruction of Mrs. Dubose's camellia bushes. After a particularly vitriolic tirade, in which she claims "Your father's no better than the niggers and trash he works for!", Jem has a bit of a meltdown. On the way back from town, he notices she is absent from her porch. Taking that as his cue, he grabs Scout's baton & cuts the flowers off every bush. It is the one time we see Jem lose his temper in a manner we might expect from Scout. Yet it leads to a very significant moment in the childrens' lives.
By the last week that Scout and Jem go to Mrs. Henry Lafayette Dubose's house to read to her, Scout realizes that Mrs. Dubose manages to stay awake and coherent "for nearly two hours with no intention of having a fit." In the beginning, the children's visits had been rather short; they were released when Mrs. Dubose's alarm clock sounded and Jessie, her caregiver, asked the Scout and Jem to leave because it was time for her to give her Mrs. Dubose her medicine. This increasing amount of time between doses of medicine is indicative of Mrs. Dubose's success in breaking her long-time addiction to morphine, the fact of which Atticus Finch reveals to his children after her death.