At the beginning of the series, the McGill family moves into number 612, which is directly behind the Johanssen Family on Kimball Street. After the McGill family moves back to NYC in Good-bye Stacey, Good-bye, Jessi's family moves into number 612.
Some families on this street are rather rude and racist to Jessi's family when they first move into the neighborhood. Fawcett Avenue is a tidy, shady street. Most houses have flower gardens, and lots of kids live there.
In Kristy and the Missing Fortune, the Dodson family calls the BSC for a plant sitting job. They do have kids, but they were going to Florida in the book. Mrs. Dodson leaves Jessi, the plant sitter, three pages of information. She lives down the street from Jessi.