Aunt Alexandra has very strict views on breeding and family. She is anxious to impress upon Scout and Jem that they come of an old, well-established and upstanding family and that therefore they should always be polite, genteel and well-behaved. This leads to comic conflict with Scout who does not want to be polite and ladylike. Atticus, too, comically fails in his duty to instil family pride in his children - it turns out that he has only told them about more colourful family characters like Cousin Joshua who went mad, rather than about the exemplary ancestors that Alexandra is obsessed with.
Alexandra seems to see people less as individuals than as products of their family background and defines them accordingly. She classes everyone in Maycomb in this way, to Scout's bemusement, and tries to stop Scout and Jem from mixing with the wrong sorts of people, that is to say people from lower-class backgrounds, or different race. The young Scout sees her as nothing but a nuisance at first. However Scout gradually does come to realise that there is merit in behaving in a dignified, ladylike manner - not from a false sense of family pride, as Alexandra would have it, but from genuinely good and civilised personal values.