Lexie is the younger half-sister of Meredith Grey. She was born to Meredith's father Thatcher Grey and his wife Susan. She also has a younger sister named Molly. Lexie had a markedly different upbringing than Meredith, who was rebellious and less social. Lexie was popular in school, voted prom queen and was her class valedictorian. Meredith at first is cold to Lexie but eventually realizes that she is taking the issues she has with her parents out on her half-sister, who only wants to get to know Meredith and work alongside her.Introduced in the third season as a new intern after the death of her mother, Lexie is charming and genuinely excited by life and her work. She is an eternal optimist, looking for the best in the people around her and trying to make the best out of most any situation. She has a photographic memory, which has helped her solve some complicated medical cases and earned her the nickname Lexipedia from Alex Karev. Lexie, perhaps emboldened by her connection with Meredith, stands up for herself and her fellow interns when some of the residents mistreat them early on, but she generally relents and follows the residents' orders. Lexie is also naive, at times, which leads to some questionable decisions in her love life. Show less «