Katie Cassidy made a splash on this season of "Gossip Girl"

24-year-old Katie Cassidy is David's daughter with model Sherry Williams, who he dated on and off in the '70s and '80s. Katie was raised by her mother and her step-father, ER doctor Richard Benedon, but as "Celebrity Apprentice" viewers saw tonight, she remains close to her famous father. Though he struggled to raise money for his team, Katie donated a grand to the cause.

Katie first significant acting gig was a recurring guest spot on "7th Heaven" in 2005. She had small roles in a few movies after that, but her true breakout was as the demon Ruby on the third season of The CW's "Supernatural."

Katie opted not to return for Season 4, instead taking a lead role in CBS's "Harper's Island," a 13-episode horror mini-series. She then went on to play Ella Simms on The CW's ill-fated "Melrose Place." Her character, a reboot of Heather Locklear's Amanda Woodward, was arguably the best thing about the show.

When "Melrose Place" was canceled, The CW didn't want to let Katie go. She made a splash on this season of "Gossip Girl" as Juliet, who came precariously close to ruining Serena's (Blake Lively) life.