In To Kill a Mockingbird, Harper Lee presents the Finch family life as the ideal. Atticus may be a single father who's raising two kids on his own, but Lee accentuates the fact that a family doesn't have to be nuclear in order to have a good life. Through them, as well as the other families in the small town of Maycomb, Lee actually explores the theme of family life.
The Finch family is a middle-class family—Atticus is a lawyer who makes a decent living, and his two children, Scout and Jem, are excellent students.
The most important thing about the Finch family, however, is their way of living and their perspective on life and the world. Atticus is a kind, compassionate and just man who teaches his children about humanity, equality and tolerance.
He always finds time for his kids, and he loves to read to them and play with them. In chapter 2, Scout remembers how she learned to read with her father:
I could not remember when the lines above Atticus's moving finger separated into words, but I had stared at them all the evenings in my memory ... anything Atticus happened to be reading when I crawled into his lap every night.
When Scout's school teachers insist that Atticus doesn't know how to teach his children and that they should stop listening to him and reading books with him, Scout decides to no longer go to school, but Atticus comes up with a good solution:
Do you know what a compromise is? ... [It's] an agreement reached by mutual concessions. It works this way. ... If you'll concede the necessity of going to school, we'll go on reading every night just as we always have. Is it a bargain?
With this he shows that he's always supportive of his children and that he values their opinions and emotions. He insists they call him by his name instead of "dad" or "father," because he wants them to be mature and open-minded, as if they are his equals. His main goal is for his kids to grow up into decent human beings, who will not discriminate and will treat everyone with kindness and respect. He especially teaches them about the evils of racism and tries to make them understand that everyone is equal and shouldn't be judged by the color of their skin.
The kids have the privilege to experience the joys of childhood, surrounded by people who love them, and spend their days having fun teasing each other, playing with their best friend Dill, and acting like their favorite characters from the books they read or Atticus reads to them. They particularly enjoy playing in the yard of the Radley family, who live near to the Finch family and are considered a bit odd in the community, as they're reclusive and not very social.
Aunt Alexandra is stricter, somewhat self-righteous, formal, and obsessed with family history and heritage. She spends her days gossiping and trying to encourage Scout, who's a tomboy, to dress and act more like a lady, as well as to encourage everyone else to respect and honor their family's history, which, according to her, is incredibly important. She may seem a bit too prim and proper and a lot less tolerant than her brother, especially when it comes to race and class, but she doesn't have any ill intentions—it's clear that she cares about her family a lot.