Mooney picked up where she left off in Auckland on Friday, smashing 70 from 42 balls in Tauranga.
The stand-in wicketkeeper combined for a 57-run opening stand with Georgia Voll (36) to again stun the White Ferns with an early onslaught.
Mooney is averaging 145 for the series after smashing an unbeaten 75 two days ago in a player-of-the-match performance in her 200th international.
No.3 Phoebe Litchfield also contributed 32, while Ellyse Perry (29 not out) and promoted Annabel Sutherland (23no) powered Australia past 200 on the final ball of the innings.
Star allrounder Amelia Kerr (1-27) was the pick of New Zealand's bowlers, but the hosts have only managed five wickets across the first two games of the series.
After the crushing eight-wicket win on Friday, Australia made just one forced change for the second match.
Star allrounder Ashleigh Gardner suffered a fractured finger while fielding in game one, forcing her to return to Sydney for further scans and seek specialist advice.
Replacing her is star Alana King, who will again partner Georgia Wareham as a fellow legspinner.
New Zealand went in with an unchanged XI.
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