Lily van der Woodsen (Kelly Rutherford) is the mother of Serena (Blake Lively) and Eric van der Woodsen (Connor Paolo). She has a stepson Dan Humphrey (Penn Badgley) a stepdaughter Jenny Humphrey (Taylor Momsen) and an adopted son Chuck Bass (Ed Westwick).
Lily was a former ballerina and a rock groupie in the 80's, during which she was involved with Rufus Humphrey (Matthew Settle). After she left Rufus she married Serena and Eric's father. She later divorced him and married two other rich men.
Lily is from a wealthy family and lived as indulgently as Serena during her wild child years. The similarity with her daughter is easily seen when she cries and is unable to make any decisions. She was also institutionalized at 19, like her son Eric.
Lily cares a lot about appearances and status in high society. She is the mom of the coolest and most popular girl at Constance Billiard School. At the end of Season 1, Lily gets engaged and marries Bart Bass (Robert John Burke) despite she and Rufus agreeing they are in love before the wedding. After Bart's death, Lily marries Rufus in Season 3.
"Don't try to be cute, okay, those days are long behind you."
"No need to rehash details of decades pass.So I moved on."
"Just stay out of my life, Rufus."
"Excuse me. Thank you Blair but it's not exactly your business what I do with my daughter. If anything your one of the reasons that I'm having to take such strong actions."