Sandals was born and raised in the Guelph, Ontario area as Liz MacNaughton.

Her father, Earl MacNaughton was the founding dean of the College of Physics at the University of Guelph.

[3] Sandals was the recipient of the first Outstanding Contribution to Education Award, granted by the Ontario Principals' Council.

While she was a past supporter of the Progressive Conservative Party and worked for the 1995 campaign of rival Tory MPP Brenda Elliott,[6][7] Sandals defeated Elliott in the Ontario provincial election of 2003 by 2,872 votes in the riding of Guelph—Wellington.

After being re-elected in 2007 in the redistributed riding of Guelph, she was again appointed as parliamentary assistant to portfolios including education and transportation.