The opening sentences of Part Two are a good example of how Jem is maturing and how Scout is slowly drawing apart from her brother. Jem is going through the initial stages of puberty, but Scout wonders if he has a "tapeworm."
Jem was twelve. He was difficult to live with, inconsistent, moody. His appetite was appalling, and he told me so many times to stop pestering him I consulted Atticus. Atticus said... Jem was growing. (Chapter 12)
With the addition of Aunt Alexandra to the household, the Finches become even more unique in there neighborhood. Jem and Scout are the only schoolchildren (Cecil Jacobs is the closest, and he lives at the far end of the block). The other neighbors (Miss Stephanie, Miss Maudie, Miss Rachel) are either widows or single (Boo and Nathan Radley, Mr. Avery). The biggest differences come as the trial grows near, and Jem and Scout find themselves the subject of gossip.
Although we heard no more about the Finch family from Aunt Alexandra, we heard plenty from the town... and sometimes hear "There's his chillun," or, "Yonder's some Finches." (Chapter 14)