McGranger was born to Bruce and Audrey. She originally was a primary school teacher who trained at the Riverina College of Advanced Education in Wagga Wagga, New South Wales, in 1975 where she had her initial actor training. She started her career in stage roles, early roles included Rose in "Bye Bye Birdie" and Anita in "West Side Story". After further experience with the Q Theatre in Penrith, west of Sydney, she started working in television and won a small part in soap opera "The Flying Doctors".