According to their payments document she can still pay cash at the post office for rates payments.
"AT ANY AUSTRALIAN POST OUTLET - for RATES payments only The Australia Post service excludes some small rural postal outlets that only provide post box facilities. Use the deposit slip provided at the bottom on the front page of your Rates Notice. You can pay the Full Balance or Quarterly Balance or part payments at the Post Office. Payments after the due date will be accepted at the Post Office. Payments accepted by Cash, Cheque, Money Order or EFTPOS - savings or cheque account only"
