Aunt Alexandra disapproves of Scout's clothes and personality. Alexandra wants Scout to be more ladylike, dress more ladylike, and hangout with females.
Aunt Alexandra disapproves of the kids not being so factual about their families history, which Atticus doesn't like Alexandra's opinion on this.
Aunt Alexandra also disapproves of the kids going to the black church with Calpurnia. Alexandra forbids Scout from going over to Calpurnia's house and community because they are black.