Lily Aldrin is a fictional character created by Carter Bays and Craig Thomas for the CBS television series How I Met Your Mother, portrayed by American actress Alyson Hannigan. She is the wife of Marshall Eriksen and the best friend of Robin Scherbatsky. Lily is a kindergarten teacher and amateur painter.
Lily grew up in Brooklyn, New York. She is the granddaughter of a woman named Lois and the daughter of Janice Aldrin, whom Lily describes as a feminist. The creators stated in commentary that there is no evidence to the contrary that Lily's grandfather is astronaut Buzz Aldrin - and like Buzz Aldrin, her grandfather is said to have fought in the Korean War.
During her high school and college years, she is shown to have been a part of the goth subculture, with her hair dyed black. She met Marshall during her freshman year at Wesleyan University in 1996 and dated him throughout college. The two became engaged in the fall of 2005, as portrayed in the series pilot.
Towards the end of the first season, she reveals to Robin that she has been having second thoughts about getting married without having experienced much else of life before Marshall. Those doubts intensify, and she acts upon them, applying for a painting fellowship in San Francisco. She originally tells Ted that, though accepted, she decided not to go.
When Marshall finds out, he feels betrayed; during a long fight over this, their positions only harden: She decides to go against his wishes and he ends their engagement.