Water: A History

Marie is the oldest woman in the colony of Isla on the parched desert planet of Quányuán and the last living person with direct memories of Earth. A sarcastic loner, she enjoys her position and uses it to tell elaborate lies about her past and keep people distant—until she meets 16-year-old Lian, who genuinely wants to know: "What was Earth like?"
Reprinted in THROUGH SPACES.