From Castle Hill in Western Sydney, Garnett played at three NAB AFLW Under-18 Championships for NSW/ACT as a junior. Able to play as both a forward and a defender, Garnett played a key role in the East Coast Eagles’ push to the AFL Sydney Grand Final in 2019. Drafted ahead of the 2020 season, Garnett is a lively and popular member of the GIANTS' squad. After a breakout 2021 season, Garnett took home the Rising Star and Community Awards at the Gabrielle Trainor Medal.