Jeffreys attended Brisbane State High School before beginning her media career in August 2005 at the Nine Network in Brisbane, working as a script assistant in the newsroom. She completed a Bachelor of Journalism/Bachelor of Arts at the University of Queensland whilst honing her skills in the production office.
Jeffreys is currently news presenter on Today. In 2008, she began filing lifestyle stories on Queensland"s Extra program, before returning to the newsroom in 2009. In 2011, Jeffreys was appointed weekend weather presenter on Nine News Brisbane.
Sylvia reported on many news events as a reporter and weather presenter for Nine News Brisbane including the floods in Central Queensland, Brisbane, Ipswich and Grantham.
She also travelled to Tully to report on the damage carved by Cyclone Yasi. In January 2012, Sylvia moved to Sydney to join Today as a New South Wales reporter.
She remained a reporter on the show until June 2013 and was replaced by Natalia Cooper. She then joined Nine News as a reporter and a fill in presenter on Nine Morning News, Nine Afternoon News, Weekend Today and Today.
In June 2014, Jeffreys joined Today as news presenter replacing Georgie Gardner.
