While Luca would be free to leave the facility 14 days after her positive test, the rest of the family would need to complete a further 10 days of isolation after this date.
These goalposts shifted again on Friday when Sam also received a positive test result, resetting the clock again.
The family now face a scenario where Luca will be eligible for release on February 5, followed by Sam on February 14.
Mrs Williamson and Maya would have another 10 days in isolation on top of that, although their clock could be reset again if either tested positive.
That means the pair will be in quarantine for at least 40 days.
Mr Williamson moved into a separate room yesterday so he could start 10 days isolating by himself and potentially be ready to take the two older girls back to Dunedin earlier.
Mrs Williamson said the situation had families in quarantine trying desperately to infect each other with Covid-19 so they could be released sooner.
"That's what we tried to do, we're sharing toothbrushes, drinking out of water bottles, not cleaning our hands."
The family were restricted to two hotel rooms and were allowed outside to an exercise yard for 30 minutes a day.
The first days of quarantine went well, as the family hunkered down with movies, board games and craft activities.
But the children were starting to struggle with isolation after two weeks.
"They asked me how long we're going to be here and I said to Luca today, '14 more days', and she just started crying. She wants to go home."
Mrs Williamson said she did not see the point of such extended stays any more when Omicron was now in the community, with cases allowed to isolate at home.
"The Government trusted us to isolate at home when we were infected in the last two lockdowns, so I don't really see what the difference is.
"Any other time when someone's infected you isolate at home and the Government just trust you to do the right thing. You don't need to lock us up like this any more."
The family had flown to Sydney on December 19 to spend Christmas with Mrs Williamson's family, and were originally due to return on January 17, to take advantage of the commencement of self-isolation at home.
Mrs Williamson said she had only seen her family once since the start of the pandemic, and they knew there could be a risk the self-isolation trial would be cancelled or postponed.
"You know you're taking a risk, but you know that that emotional side takes over from the logical side and you just want to go and be with your family."
Unfortunately, just days after they arrived in Australia, the Government announced self-isolation would be suspended until at least the end of February.
The family were prepared for spending 10 days in MIQ if need be, but were not aware that could be extended further with each new positive test.
