A point guard, she began her college basketball career at Oregon before transferring to Nebraska after her sophomore season.

[6] In her youth career, she also played for the Moe Meteors of the Country Basketball League,[7] and the Southern Peninsula Sharks.

[9] After debuting for the Southern Peninsula Sharks in the Big V in 2015,[10] Shelley moved to Canberra in 2016 to train full-time at the Australian Institute of Sport (AIS).

[10] She returned to the Southern Peninsula Sharks for the 2018 Big V season, where she averaged 17.9 points, 5.2 rebounds, 5.0 assists and 3.6 steals per game.

[12] On 16 March 2018, Shelley signed an amateur contract with the Melbourne Boomers of the Women's National Basketball League (WNBL) for the 2018–19 season.

She was drawn to Oregon by its facilities and culture, with many international players on the team, and felt that the program would prepare her for a professional career.

During the game, Shelley scored a season-high 32 points and set a program single-game record with 10 three-pointers in an 84–41 win over UC Riverside.

Shelley chose Nebraska because of her relationship with the coaching staff and to play alongside her longtime friend, Isabelle Bourne.

[4] On 20 November, she registered the fourth triple-double in program history, with 14 points, 10 rebounds and 10 assists in 20 minutes, helping her team defeat North Carolina Central, 113–58.

She averaged 18.8 points, 3.3 steals and 3 assists per game, leading the tournament in each category, and helped her team win a gold medal.

[51][52] At the semifinals of the 2016 FIBA Under-17 World Championship in Spain, she scored 23 points to lead Australia to a 73–63 upset win over the United States, who had previously been undefeated in the tournament's four-year history.

[54] She was a member of the bronze medal-winning Australian team at the 2018 FIBA Under-18 Asian Championship in India, averaging 8.8 points, 7 rebounds and 4.8 assists per game.

[55] Shelley averaged 8.6 points, 5.4 rebounds and 3.7 assists per game at the 2019 FIBA Under-19 World Cup in Thailand, where Australia won the silver medal.

[56] Shelley earned her first selection to the Australian senior national team in July 2020, making the 23-player preliminary roster for the 2020 Summer Olympics.

[58] Shelley played for Australia at the 2021 FIBA Asia Cup in Jordan, where she averaged four points in under 13 minutes per game, as her team won the bronze medal.