They were all cousins. Myra. Peg. Tristin. Very distant cousins. Leigh's cynical side–her only side–told her that Peg and Tristin adopted the titles of 'aunt' and 'uncle' to make a statement. They were in charge. They'd be calling the shots.
-- Narrator (One)

Importance: In this quote, Leigh is looking at Tristin and Peg with a cynical eye. Someone else might possibly assume that Tristin and Peg chose the titles of Aunt and Uncle not to make any type of statement, but simply in recognition of the age gap between themselves and Leigh. Indeed, it would also be possible that they chose those names to forge a sense of familial bonding between themselves and Leigh. However, Leigh, being cynical, traumatized, and not wanting to make any such bonds, assumes their using the titles of Aunt and Uncle must be a statement of control.

Point is, find the right ones to let in...
-- Tyrone Milbank (Chapter Three)