Rambin appeared on NBC's new series, Lipstick Jungle. Leven filmed a pilot presentation for the CW titled Austin Golden Hour, directed by Sanford Bookstaver. Leven made her feature film debut in Killer Film's independent picture, Gigantic (2008). The film starred Paul Dano. Rambin joined the cast of Terminator: The Sarah Connor Chronicles, playing the character Riley Dawson, a school friend and love interest of John Connor. Rambin left the show after filming her last episode "Ourselves Alone".. Rambin landed a recurring role as Sloan Riley, the 18-year-old-daughter of Dr. Mark Sloan on the medical-drama, Grey's Anatomy. Rambin briefly returned to All My Children as Lily Montgomery on January 5, 2010 for the show's 40th Anniversary.
In 2010, Rambin appeared as the daughter of Virginia Madsen's and David James Elliott's characters on the ABC television series, Scoundrels. However, the series ended its eight-episode run on August 15, 2010, due to low ratings. Rambin appeared on the Disney Channel show, Wizards of Waverly Place, in the recurring role of Rosie, who is a Guardian Angel turned Angel of Darkness who was in love with Justin to steal the Moral Compass; Rambin made her debut on the episode "Everything Rosie for Justin" and left the show after the episode "Wizards vs. Angels". Later, Rambin was cast in the recurring role of Chloe Hall, on the long-running CW series, One Tree Hill. Then later, Rambin was cast as Molly Sloan on the CBS crime-drama CSI: Miami.