the first time Reed ever saw the Billings girls she was in her Dorm and could see Noelle, kiran, Arianna, and Taylor in Noelle's room the the Billings dorm. She was all but "licking the glass". So noelle started to call her Glasslicker
Because the first time Reed sees the main four Billings girls, she has her face pressed against the window at Bradwell, and they see her staring at them