The Sixers trio were key figures in the Southern Stars' two warm-up fixtures against the England Women's Academy in Loughborough last week.
In a rain-affected opening match, Perry picked up figures of 1/12 as the England Women's Academy was restricted to 7/184 from their 39 overs. Healy (35 off 28), and later Perry (38 off 45), set the platform for the Australian run-chase, with the Southern Stars passing the total in the 32nd over with 6 wickets in hand.
In the second fixture, Healy (52 off 59) and Perry (46 off 51) were amongst the runs again, as Australia set about posting an imposing total for the home side to chase.
However, it was the destructive hitting of Gardner (59 not out off 31) that really caught the eye as the Southern Stars finished with 5/337 from their 50 overs.
Gardner (2/19) and Perry (2/29) both chimed in with the ball as the England Women's Academy was restricted to 9/269 from their 50 overs.
The Women's Ashes gets underway with the first ODI starting at 11pm on Tuesday night.