[11][12] She began WBBL|03 in commanding fashion with an innings of 114 off 52 balls against the Melbourne Stars at North Sydney Oval, recording the league's fastest half-century and highest individual score.

[14] She was cleared to play in the final of the 2018–19 WNCL season, having been a late withdrawal from the previous match due to suffering mild concussion during warm-ups,[15] managing 30 not out with the bat and 2/36 with the ball in the 33-run victory over Queensland.

[20] Gardner was named in Australia's squad for a home 2016–17 series against New Zealand,[21] and made her Women's Twenty20 International (WT20I) debut on 17 February at the Melbourne Cricket Ground, but was run out for a golden duck in the 40-run win.

[23] Touring New Zealand with the Australian squad for the 2016–17 Rose Bowl series, Gardner made her Women's One Day International (WODI) debut on 2 March at Bay Oval.

After taking three wickets in the ODI at Allan Border Field, she scored 27 off 18 deliveries late in the run chase to help clinch a narrow two-wicket victory with five balls to spare.

[33] In a Tri-Nation Series match against India at the Junction Oval on 8 February 2020, Gardner recorded her highest T20I score, compiling 93 runs from 57 balls despite her team suffering a seven-wicket loss.

[39] During a group stage match of the 2022 Women's Cricket World Cup against New Zealand at the Basin Reserve, Gardner played a dominant innings of 48 not out from 18 balls while also taking 3/15, contributing to her team's 141-run victory.

Gardner made a strong start to the T20I tournament at the 2022 Commonwealth Games, scoring 52 not out off 35 balls against India, ensuring Australia's recovery from 5/49 to successfully chase down a target of 155 with three wickets in hand and an over to spare.

[48][49] An Indigenous Australian through her mother's Muruwari heritage,[50][51] she formed the Ashleigh Gardner Foundation with the goal to "increase the percentage of Aboriginal kids finishing high school".