After graduating from Columbia University in 1998, Ms. Lakhani, who is 32, took a job teaching 7th grade English at Dalton. She quickly became dissatisfied with her measly teacher's salary and began taking on after-school tutoring gigs--jobs that can pay upwards of $350 an hour--with what she called "high-profile Manhattan families." And thus Ms. Lakhani began to enjoy a lifestyle of Chanel handbags and splurges on designer make-up at Henri Bendel. (A brown-and-white shopping bag very similar to Bendel's adorns the cover of Ms. Lakhani's book.) She eventually left Dalton, where she had become chair of the middle school English department, after eight years.