Alyson Lee Hannigan is an American actress. She is best known for her role as Willow Rosenberg on the television series Buffy the Vampire Slayer. She currently plays Lily Aldrin on the CBS sitcom How I Met Your Mother. She also played flutist Michelle Flaherty-Levenstein in three American Pie films.Hannigan previously dated Ginger Fish of Marilyn Manson. She later married actor Alexis Denisof (who played Wesley Wyndam-Pryce in the Buffy/Angel franchise) at Two Bunch Palms Resort in Desert Hot Springs, California on October 11, 2003. They bought a house together in Santa Monica, California.It was announced on October 22, 2008 that she was pregnant with their first child. Her daughter, Satyana Denisof, was born on Hannigan's 35th birthday, March 24, 2009.