Raised in the Victorian country town of Nhill, Stephan's senior rowing was from the Melbourne University Boat Club.

[6] Stephan was first selected to represent Victoria in the women's youth eight in 2011 contesting the Bicentennial Cup at the Interstate Regatta within the Australian Rowing Championships.

With Charlotte Sutherland, Alexandra Hagan and Hannah Vermeersch, Stephan won gold and an U23 World Championship title.

[14] Two months later that same four raced as Australia's senior women's coxless four at the 2013 World Rowing Championships in Chungju, Korea and took a bronze medal.

[14] Stephan was a member of the Australian women's eight who initially missed qualification for the 2016 Rio Olympics but received a late call up following the Russian drug scandal.

The crew had dispersed two months earlier after their failure to qualify but reconvened, travelled at the last minute to Rio and borrowed a shell.

[15] After the Olympics Stephan continued to compete at the highest level and in 2017 she was selected at bow in Australia's coxless four with Molly Goodman, Katrina Werry, and Sarah Hawe.

In the final sprint, Stephan called Goodman to up the rating and at 43 strokes per minute, the Australian four surged to the lead to claim gold and the world championship title ahead of Poland and Russia.

[14] Stephan, Aldersey, Werry and Hawe were selected to race Australia's coxless four at the 2019 World Rowing Championships in Linz, Austria.

[14] By the time of national team selections in 2021 for the delayed Tokyo Olympics, Stephan was the sole member of the crew who had qualified the Australian coxless four on its 2019 performances.

In the final with Stephan making the race calls from the bow, they led from the start, were challenged hard to the finish by the Dutch crew but took the gold in an Olympic best time.

[14] Stephan was selected in the Australian women's sweep squad to prepare for the 2022 international season and the 2022 World Rowing Championships.

[14] In 2023 Stephan rejoined her two-time world champion crewmates of Katrina Werry and Sarah Hawe with new addition Giorgia Patten in the Australian women's coxless four for the 2023 international season.