[1][2] Her early sporting career was as a track and field athlete and she won two silver medals in the 800 m at the FESPIC Games.

[1] Johnson won a silver medal at the 2008 Beijing Games in the Women's 1 km Time Trial B VI 1–3 event with her pilot Katie Parker.

[3] At the 2012 London Paralympics, she won a gold medal in the Women's 1 km Time Trial B with her pilot Stephanie Morton.

[3] In 2014, she was paired with pilot Holly Takos and competed in the Glasgow Commonwealth Games where the South Australian duo placed fourth.

Johnson won the National Achievement Award for Best Newcomer in 2007, and was twice named Blind Sportsperson of the Year, in 2010 and 2011.