Aunt Estée is a character in The Testaments.
As Aunt's names are chosen to be comforting by referencing things women liked from the "time before," Aunt Estée's name likely references Estée Lauder, a businesswoman who started a makeup and haircare company of the same name.
Aunt Estée taught young Daughters Crafts, including Agnes MacKenzie. She was the Daughters' favorite teacher, and would say that the strict warnings of Aunt Vidala were going over the top, and instead focused on the happiness of the Daughters' future married lives. She taught Daughters that the right men would respect them and take care of them once they were married.
She taught Daughters that going into their fathers' studies would contain things too complex for them to understand, and likened it to "teaching a cat to crochet," which would make the girls laugh.
Agnes graduates from the Vidala School when she gets her period and starts class at Rubies Premarital Prepatory. However, Agnes returns to the Vidala School just before her arranged marriage to B. Frederick Judd, confiding in Aunt Estée about her worries. Estée is responsible for bringing Agnes to Ardua Hall to begin her training as a Supplicant Aunt.