Smit-McPhee was born in Adelaide to Sonja Smit and Andy McPhee, an actor and former professional wrestler.
[3] After signing to her father's agents, Smit-McPhee secured a role in police drama Blue Heelers as a girl with gender dysphoria.
[2] Shortly after, she won the role of Bree Timmins in the long-running Australian TV series Neighbours, which she played from 2005 to 2007.
[2][4] After leaving Neighbours, Smit-McPhee starred in the children's television series As the Bell Rings, which aired on the Disney Channel.
[12] After living in Los Angeles for around ten years, Smit-McPhee moved back to Australia to launch her music career.