Who are the direct and indirect characters in "The Scarlet Ibis"?

I think you are asking which characters are characterized directly, and which characters are characterized indirectly.

Remember, direct characterization only happens when the author actually states something about a character's traits.  One example of this type of characterization is the narrator's statement that "Doodle was about the craziest brother a boy ever had."

Indirect characterization happens when the author uses a character's actions or words to show us something about that character.  The author shows us that Doodle is an imaginative child by having Doodle tell beautiful stories.

None of the big characters in "The Scarlet Ibis" are characterized in one way or the other.  All are characterized directly and indirectly.