Scout and Jem are not happy about their Aunt Alexandra coming to live with them. She is not the warmest or friendliest person in the world. She has a lot of rules and enforces them strictly. Scout describes her as similar to a mountain.
Aunt Alexandra would have been analogous to Mount Everest: throughout my early life, she was cold and there.
Aunt Alexandra adheres to the traditional southern view of etiquette, so she is especially hard on Scout for acting too much like a boy all of the time. It becomes a mission to turn Scout into a lady. Scout and Jem are not out right rude to her. They accept Atticus's decision to have Aunt Alexandra stay with them, but the kids are not thrilled about it.
Atticus is not necessarily thrilled about it either, but he is the one that did ask for her presence. He knows that his sister runs a tight ship, but he also believes that her presence will have a positive effect on his children as well . . . especially Scout.
"We felt it was time you children needed--well, it's like this, Scout... Your aunt's doing me a favor as well as you all. I can't stay here all day with you, and the summer's going to be a hot one."
For most of Aunt Alexandra's household decisions Atticus remains ambivalent. He is working on the case, and he see that Aunt Alexandra is taking good care of the kids. But that doesn't mean Atticus doesn't pay attention and put his foot down against her wishes every once in awhile. Aunt Alexandra, at one point, tell Atticus to fire Calpurnia. He flat out refuses.
Lastly, Maycomb welcomes Aunt Alexandra with open arms. They love her. Certain residents stop by to bring her baked goods. She has afternoon coffee and gossip with Miss Crawford. She involves herself with a couple of clubs and societies. She's the perfect Maycomb socialite. Scout describes it like this:
"Aunt Alexandra fitted into the world of Maycomb like a hand into a glove, but never into the world of Jem and me."