The woman was on holiday during Queen’s Birthday weekend with her husband and close friends when she won Powerball First Division.
She was “pretty excited” to see an email from MyLotto saying she had won a prize.
“I thought I must have won around $1000,” she said.
She watched the draw online and as the numbers lined up and corresponded to those on her ticket, she shouted to her friends and husband that she’d just won $16,500.
“We all stated celebrating straight away. I was over the moon,” she said.
“My friend took one look at the ticket and said ‘hang on, you’ve actually won a bit more than that - you’ve missed a few zeroes.
“He handed me back the phone and my husband and I took a good look at the number again - that’s when we realised what we thought were full stops were actually commas, and we’d really won $16.5 million.”
Plenty of tears were shed when the couple told their children over the phone.
“It’s absolutely life-changing. This prize is going to make such a huge difference to our lives - and the lives of our family.
"We’re going to use the winnings to set ourselves up for retirement and make sure the kids are looked after.
"It’s truly unbelievable to think that we can do all the things we’ve dreamed of doing over the years.”