I'm not sure that the word "tomboy" is ever actually used to describe Scout within the text of To Kill a Mockingbird, but author Harper Lee has modeled Atticus's daughter after herself. Harper Lee has been described as a "rough 'n' tough tomboy" growing up in Monroeville, Alabama, and Scout can easily be influenced when Jem accuses her of "gettin' more like a girl every day." One symbol of Scout's tomboyishness is her favorite article of clothing: her overalls. After the attack by Bob Ewell, Aunt Alexandra lovingly
... brought me my overalls. "Put these on, darling," she said, handing me the garments she most despised. (Chapter 28)
Aunt Alexandra attempts to change Scout's ways, inviting her to meet some ladies.
When I appeared in the doorway, Aunty would look as if she regretted her request; I was usually mud-splashed or covered with sand. (Chapter 13)
At the Missionary Circle meeting, Aunt Alexandra invites Scout to stay with them.
This was part of her campaign to make me a lady.
... Miss Maudie's gold bridgework twinkled. "You're might dressed up, Jean Louise," she said. "Where are your britches today?"
"Under my dress."
... Miss Stephanie eyed me suspiciously. "Well you won't get very far until you start wearing dresses more often." (Chapter 24)
And then there are her fights with boys.
Catching Walter Cunningham in the schoolyard gave me some pleasure, but when I was rubbing his nose in the dirt Jem came by and told me to stop. "You're bigger than he is," he said. (Chapter 3)