31 parts Ongoing Allison "Lizzie" Grey, younger sister of Lexie Grey is a prodigal genius. With an IQ of 206, she graduated high school when she was 9, college when she was 11 and med school when she was 13. Now that her mother has died , her father has turned into an alcoholic. She and her sister Molly have never been close so the only one who can protect her now is Lexie. When she comes with Lexie to work at Seattle Grace, she doesn't know about the drama, the challenges and the family that will meet her there.