Ever Noticed?

Have y'all ever noticed in Sarah Dessen's books that her charries seem to "live in the same world", if you know what I mean? Nate Cross was a charrie in Lock and Key--One of the main characters, actually, and he's mentioned in Along for the Ride...Auden used to have a crush on him at her school--Perkins Day, which is mentioned in several of her books. Also, in Along for the Ride, Auden is in a town called Colby. So is Colie in Keeping the Moon. Colie works at the Last Chance. Auden, in Along for the Ride, goes to the Last Chance to get burgers, and sees what she notes is "A pretty girl with dark hair and a lip ring" -- Colie.
Jackson--Both the town and the school is also mentioned in several of her books. Also, a guy (I can't remember his name) is mentioned in both Lock and Key, and This Lullaby. He's Mitchell's brother or roommate or something. In This Lullaby, he's the girl's abusive boyfriend's friend who sells pot, and in Lock and Key, Ruby knows him personally.

...Am I the only one who noticed this?