Lexie Grey

Lexie Grey is a fictional character from the ABC television series Grey's Anatomy. The character is portrayed by Chyler Leigh, and was created by Shonda Rhimes. She was made an official series regular for season four.

Background
Lexie is the daughter of Thatcher Grey and his second wife, Susan. She also has a younger sister, Molly Grey Thompson. Her older half-sister is Meredith Grey, born to Thatcher and his first wife, Ellis Grey. She graduated from Harvard Medical School before being accepted in Seattle Grace's Intern Program. She was very popular in high school, having a great group of friends, being crowned prom queen, and being class valedictorian.

Season Two
Lexie is mentioned in the episode in which her sister Molly is pregnant and taken to Seattle Grace to have a surgery to help the baby breathe. When Meredith is talking to Molly about Meredith's paternal side of the family, she mentions her sister and her education at Harvard University.

Season Three
Lexie is a new intern at Seattle Grace Hospital. She was introduced in the penultimate episode of the third season in which she met Derek Shepherd at Emerald City Bar. Her mother Susan suddenly and died when Lexie was just about to start her internship at Mass General. In the third season finale, Derek confesses to Meredith he met another woman (though he doesn't specify who, since he doesn't know) and when she asks if she should be worried, he confirms her fears. Lexie would make her first appearance in Seattle Grace when she introduced herself to George O'Malley, who realized her connection to Meredith.

Season Four
She has been assigned to surgical resident Cristina Yang for her medical internship, and has already borne some striking similarities to her half sister, Meredith Grey. She tries to win Meredith over, but no matter what she does Meredith acts coldly towards her. She has entered into a relationship with Alex Karev, and seems to be taking the lifestyle of her older sister. Lexie was angry when she learned that Alex still had feelings for another woman who believed they were still a couple.

Trivia

 * She was prom queen and valedictorian in high school.