At 0630 AEST on Wednesday, the local unit was worth 74.67 US cents, up from 74.38 US cents on Tuesday.
The move came after Ms Brainard said soft inflation may yet make her reassess monetary policy.
Brainard added she still anticipates a US rate rise soon.
The local currency was stronger against the yen, but down against the strengthening euro.
Access exclusive analysis, locked news and reports with Inside Retail Weekly. Subscribe today and get our premium print publication delivered to your door every week.