Born in Cambridge, England, Barker grew up in the village of Oakington, near Cambridge, and attended Impington Village College before undertaking a philosophy degree at the University of Southampton. After this was completed, she became a runner for independent production company Lion TV, a researcher, and eventually the sports presenter for BBC Choice programmeBackstage. She was also previously a Librarian.
On 23 June 2000, Barker joined the children's television programme Blue Peter. During her six years there, Liz reported from Vietnam, Morocco, Brazil, Austria, Greece, India and the US. Her adventures have included lawn mower racing, paragliding, walking a circus high-wire and cleaning windows at London's Canary Wharf tower.
On 25 May 2004, Barker announced that she was pregnant with her first child, by husband Michael Todd. A boy, Dexter Jack Barker Todd, was born on Saturday 4 December 2004 and featured on the show many times, including at just 13 days old, on his first birthday and on Barker's leaving date. While Barker was pregnant, scan images were also shown. She became the first presenter to rejoin Blue Peter after having a baby, but on 23 January 2006, she told viewers that she would be leaving the programme at Easter and moving away from London so she could spend more time with Dexter and the rest of her family. She was replaced by Zöe Salmon, who originally took Liz's place in December 2004 when she had her baby but she returned earlier than expected in early 2005.
On 11 April 2006, Barker left the programme, with a special This Is Your Life-style show devoted to her, containing former presenters, family, friends, and people she had met along her Blue Peter travels, including Kitty Hart-Moxon. She also announced, on her last live show, that she would be co-presenting a new CBBC show, Totally Doctor Who, with CBBC's Barney Harwood; the first episode was broadcast on 13 April 2006. However she did not return for Totally's second series, and was replaced by SMart's Kirsten O'Brien.
On 18 September 2006 it was announced on Blue Peter that Liz was due to have another baby and on 20 February 2007, it was announced on Blue Peter that she had given birth to a girl called Poppy.
Liz has also appeared in Carrie's War (2004) in an uncredited role.
|Blue Peter||Herself||Main Presenter alongside Konnie Huq, Simon Thomas, and Matt Baker|
|2004||Carrie's War||Extra||Minor Role|
|Blue Peter||Herself||Main Presenter alongside Konnie Huq, Simon Thomas, Matt Baker and Zöe Salmon|
|2005||Blue Peter||Herself||Main Presenter alongside Konnie Huq, Simon Thomas, Matt Baker, Zöe Salmon and Gethin Jones|
|Totally Blue Peter||Main Character||2 Part Drama|
|2006||Blue Peter||Herself||Main Presenter until April 2006 alongside Konnie Huq, Matt Baker, Zöe Salmon and Gethin Jones.|
|Totally Doctor Who||Herself||Main Presenter alongside Barney Harwood|
|2007||Buzz! Junior: Jungle Party||Herself||Voiceover|