The couple announced their engagement in June after about three years of dating.
Their wedding date was not announced, the Web site said, adding Kerr canceled an appearance at the Australian department store David Jones this week to celebrate the happy occasion.
"David Jones very graciously released me during this period so we could celebrate an intimate ceremony and honeymoon together," she said. "I'm very much a part of the David Jones family and I am very committed to my role. I am enormously grateful to David Jones to have been given this time to enjoy such a special moment in my life."