Lily Aldrin (Alyson Hannigan) is a kindergarten teacher and an aspiring artist. Lily was originall engaged to Marshall before they broke it off for her to try and be an artist in California. However, she returned to him after her fellowship ended and the two quickly married by the end of season two.
Robin: Guys are like the subway. You miss one, another comes along in five minutes.
Lily: Unless it's the end of the night, then you get on anything!
Ted: I just got screwed by my two best friends and I didn't even know it
Lily: In Canada that's called a sneaky snowflake