When Kristy's stepfather (who she had once been very resentful of) has a heart attack, she tells the 911 operator that "Something is wrong with my dad!"
Throughout the series, Watson rarely refers to Kristy as "my stepdaughter." Even when he's writing to a relative of his, he refers to her as "my daughter."
Byron finally deciding to befriend Nicky in a later book.
When Claudia is accused of cheating on a math test, her parents say that they would "like to believe" her when she says that she's innocent. Her older sister Janine says, "I do believe you," and is so vehement in her defense of Claudia that she makes their parents ashamed of the fact that they had ever doubted her.