From Halopedia, the Halo wiki
Doctor Lillian Bratton was a fifth grade homeroom teacher in the Wallace Fujikawa Elementary School in 2481. She noted that one of her students, future-Admiral Preston Cole required guidance to reach his full potential, and seemed to work too hard even when he played, overanalyzing every situation. She also suggested that his chores or responsibilities at home should be relaxed as he often fell asleep in class.
List of appearances