When Helen Goddard walked into a Canberra restaurant recently, a stranger walked up to her and went to kiss her, mistaking Helen for her twin sister Anne Cahil Lambert.
"It might have been cute when we were five but now that we're over 60, it's not so cute," Helen said.
Helen and Anne are so identical they often get confused with each other; Facebook's facial recognition algorithms even try to tag one as the other.
Now the pair are concerned how foolproof the government's new facial recognition system will be when it comes to identifying one for the other.
"The technology doesn't allow anyone to look like someone else," Helen said.
"Is someone suddenly going to say ... 'Sorry, you've already got a license; you've already got a passport; you're not getting a second one."
Helen avoids the streamlined, automated facial recognition line at airports and Anne said the pair can't apply for passports online.
"Last year I did travel and I did use the automatic scanning stuff and it seemed to work. I don't know if they thought I was Helen or not, I was just keeping my mouth shut," Anne said.
Helen described verifying their identity for a passport as "hell on a pogo stick".
Assistant Professor Bruce Baer Arnold of the University of Canberra law school said there was no way of knowing how the system would treat people like Anne and Helen.
"We don't know how the system is going to work," he said.
Assistant Professor Arnold said he saw some value in biometrics but stressed it must be wrapped up in a proper legal framework and oversight.
"We've had problems with things like DNA, where courts have been puzzled: 'Alright, did that particular person do it or not?'," he said.
According to the Australian Bureau of Statistics there were over 300,000 multiple births in Australia in 2015, with 94 in the ACT.
Assistant Professor Arnold said in a relatively small town like Canberra, Helen and Anne's chances of facing problems with the system were more likely.
"If we have say two people with what the system regards as identical biometric data, we have some confusion. It's something that we can live with as long as the law around that allows people to readily prove that it wasn't me," he said.
"Biometrics is being promoted as a silver bullet ... It's not, it's a tool. It will not work in all circumstances."