What impact did Scout have on 3 other characters in the book?

Scout has an impact on Dill, Boo Radley, and Walter Cunningham. 

Scout impacts many people in her life, of course.  She and her brother Jem are almost inseparable during the summer.  Her father Atticus and her aunt Alexandra worry about her and what kind of adult she will turn out to be.  She has a friendship with her neighbor Miss Maudie.  However, there are three characters whose lives Scout touches in such a way that she leaves a lasting impact. 

Dill is closer to Scout’s age than Jem’s.  He is a bit odd, and definitely lonely when he first comes to Maycomb.  Due to their closeness in age, they become friends despite the gender difference.  Dill even asks Scout to marry him, an innocent and childish acknowledgement of her importance to him.  Dill does not have much at home.  His father is absent, and his mother eventually remarries.  Having Scout in his life makes it much fuller.  This is why he runs away and hides under her bed. 

Scout’s impact on Boo Radley is profound. He is another very lonely person.  Boo is the reclusive, shy neighbor who watches the children in his neighborhood as if they were his own.  Scout, Jem, and Dill spark an interesting friendship with Boo through trying to get him to come out.  At first, Scout is afraid of him.  As she gets older, she comes to realize the role she has played in his life. 

Boo leaves presents for Scout and Jem in a tree knot.  He even carves little figures of them out of soap dolls.  He seems to take a special interest in the spunky Scout.  When Miss Maudie has a fire at her house, Boo sneaks out of his and leaves a blanket on her shoulders. 

“Then whose blanket is that?”

“Blanket?”

“Yes ma’am, blanket. It isn’t ours.”

I looked down and found myself clutching a brown woolen blanket I was wearing around my shoulders, squaw-fashion. (Ch. 8) 

Later, when Boo rescues Scout and Jem from Bob Ewell, she walks him home.  Standing on the Radley porch, Scout realizes how big of a role she and her brother played in his life.  They were friends, from afar.  Scout and Jem gave Boo the courage to leave his house. 

A third person Scout impacted was only around her for a brief time, but surely an event he would never forget.  When Walter Cunningham and the angry mob surrounded Atticus, trying to get at his client, Scout decided to jump into the fray and have a conversation with Mr. Cunningham.  She was hoping to trade on the fact that she was the same age as his son and the two were sort of friends.  It worked. 

Atticus said nothing. I looked around and up at Mr. Cunningham, whose face was equally impassive. Then he did a peculiar thing. He squatted down and took me by both shoulders.

“I’ll tell him you said hey, little lady,” he said. (Ch. 15) 

Scout helps Walter Cunningham, Sr. come to his senses.  Being confronted with a little girl, even though she never directly addresses the situation, helps him realize that what he is doing is wrong.  Atticus is impressed by this.  He tells Scout that every mob is made of people.  Scout addressed Walter’s humanity.