Scout finds Aunt Alexandra rather stuffy.
Scout finds Aunt Alexandra difficult to relate with because they are polar opposites. Scout loves playing in the backyard and building forts while in her overalls. Aunt Alexandra drinks tea and wears beautiful women's clothes that are all too tight and uncomfortable. This dichotomy between the two of them is easily shown in Scout's typical conversations with Aunt Alexandra:
I could never think of anything to say to her, and I sat thinking of past painful conversations between us: How are you, Jean Louise? Fine, thank you ma'am, how are you? Very well, thank you; what have you been doing with yourself? Nothin'. Don't you do anything? Nome. Certainly you have friends? Yessum. Well what do you all do? Nothin'.
Futhermore, Scout found Alexandra bossy:
Aunty had a way of declaring What Is Best For The Family, and I suppose her coming to live with us was in that category.
Scout would also call Aunt Alexandra judgmental, unfair, prissy, and hypocritical. Readers see her judgment as she criticizes Atticus for the way he raises the children. Her unfair treatment comes out when she supports Francis instead of Scout. Her prissy nature comes out because she is a Southern woman with pride:
To all parties present and participating in the life of the county, Aunt Alexandra was one of the last of her kind: she had river-boat, boarding-school manners; let any moral come along and she would uphold it; she was born in the objective case; she was an incurable gossip. When Aunt Alexandra went to school, self-doubt could not be found in any textbook, so she knew not its meaning. She was never bored, and given the slightest chance she would exercise her royal prerogative: she would arrange, advise, caution, and warn.
Her hypocrisy is only shown to a slight degree when the Missionary Tea gets together. She participates as one of the women who will gossip about the town and give money to the poor elsewhere, but help very little at home.