Born on the 24th March 1974 (making her forty years old, can you believe that?!), in Washington D.C., Alyson Hannigan is the daughter (and only child) of Emilie Haas, a Jewish real estate agent, and Al Hannigan, a truck driver with Irish ancestry. Her parents divorced when she was just two years old and she was brought up by her mother in Atlanta, Georgia as a result. Hannigan began performing very early - even as a baby she appeared in photoshoots and an instructional video for parenting - and started appearing in commercials when she was just four years old. After a handful of minor television jobs, she made her first major film appearance in 1988's My Stepmother Is An Alien, in which she starred alongside the likes of Kim Basinger, Dan Aykroyd and Seth Green - the latter whom played her boyfriend, just like he would go on to do again a decade later in Buffy The Vampire Slayer. Hannigan has, of course, famously gone on to play Willow Rosenberg in Buffy, Michelle Flaherty in the American Pie series and Lily Aldrin in How I Met Your Mother, but what other facts about the beautiful star aren't widely known? Here are ten things you didn't know about Alyson Hannigan...