In "The Scarlet Ibis," how long does it does it take to teach Doodle to walk? What does that show in each brother?

It probably takes about 9 months to a year to teach Doodle to walk. According to the text of the story, when Doodle is five, Brother begins to feel embarrassed that Doodle can't walk. He then takes him to the Old Woman Swamp and teaches him to walk. On Doodle's sixth birthday, they show the rest of the family that Doodle can walk. Thus, sometime between becoming embarrassed about having a 5-year-old brother who can't walk and Doodle's sixth birthday, Doodle learns to walk.