But she, along with the eight NZ First MPs, were out of Parliament after the party won just 2.6 per cent of the total vote in the 2020 election.
It is understood she was a well-respected by her Labour Party ministerial colleagues.
She also said she had a number of issues with the party around its election campaign and the way it was run.
Martin – who has been with the party for 12 years and has strong family connections to NZ First – said there was often policies announced that were "news to me".
Although leaving, she wished the party well.
"I think there is a party like NZ First that is needed in New Zealand ... but that's no longer NZ First."
She told the Herald that she hadn't told leader Winston Peters about her plans to resign.
In fact, she said she has had no contact with Peters – who was the deputy Prime Minister during the last term of Government – since October.
The last time they spoke was at a post-election dinner; since then they have had "no contact".
Asked about their relationship, Martin said that Peters was a "work colleague".
Peters has gone to ground since the election and has made few public appearances.
And he has done next to no media interviews either – despite repeated attempts by the Herald and other outlets.
He has not publicly resigned the leadership of NZ First – a party he founded in 1993. But former MP Darroch Ball is now the party's president.
Martin said Ball was disappointed when she told him she was leaving the party.
Looking forward, Martin said will be working for the Ministry of Education; she has a contract to work with officials around funding for teacher aides.
But she said she will also be using her extra time to spend with her family.
