Cook definitely became the breakout star of the group, hitting it big as quirky artist Laney in the 1999 teen rom-com She's All That, opposite Freddie Prinze, Jr. In 2001, she landed another cult-favourite role in Josie and the Pussycats before moving on to a more varied career that has included indie films, voice acting, and even Hallmark movies (one of which she also executive-produced).
In 2004, Cook married actor Daniel Gillies, who later gained fame of his own as noble vampire Elijah on the CW's The Vampire Diaries and its spin-off The Originals. The couple have two children. Cook also has her own production company, Ben's Sister Productions.