The woman, whom the Otago Daily Times cannot name for legal reasons, said Immigration New Zealand told her it could not consider the two young children in assessing her application.
That was "inhumane", she said.
"I can't imagine my life without my children. They need a mother in their lives."
Her greatest fear was they would grow up thinking she had deliberately abandoned them.
The woman's situation highlighted a flaw in the law concerning such cases, University of Otago law lecturer Anna High said.
"New Zealand rightly provides for a special type of visa for domestic violence victims who might otherwise feel pressured to stay in an abusive relationship for fear of losing their immigration status.
"But one of the major problems with our laws, as I see it ... is that the emphasis is more on which country a victim is from, rather than on what she stands to lose by being forced to leave her New Zealand life behind."
Dunedin lawyer Geoff Mirkin, who is handling the woman's tribunal appeal on a pro bono basis, said although such cases were complex and difficult for INZ to handle, women should not be penalised for leaving an abusive relationship and thereby giving up their path to residency.
Should her tribunal case be unsuccessful, an application to the Family Court for a relocation order, allowing her to take the young children overseas, was a potential option.
"Until such time as the tribunal makes a decision, and the Family Court can determine the future status of these children, someone needs to intervene and grant her - even if it's temporary - a right to remain in New Zealand, and to work."
Clutha-Southland MP Hamish Walker has appealed to Associate Immigration Minister Kris Faafoi for the woman's work visa to be renewed while she waits for the Immigration & Protection Tribunal to reconsider the case.
"No matter where you are in the world, you should feel free to leave an unsafe relationship," Mr Walker said.
"The emotional harm and ongoing trauma these children would endure, due to being denied their birth mother, would be the worst possible outcome for them."
INZ operations support manager Michael Carley said the agency could not comment because the matter had been appealed.
However, the agency had the ability to consider a temporary visa for people to remain in New Zealand during the tribunal appeal process.
The woman should contact the agency to discuss her options, Mr Carley said.
The woman said she left her former partner in 2017 due to physical and psychological abuse.
She said she lost her home as a result, and had no savings because he controlled their finances.
After two years of uncertainty about her immigration status, and struggling to get by financially with part-time work, she was suffering from depression.
She continued to rely on support from the Salvation Army, local support services Happiness House and Jigsaw, friends and a kind landlady.
"I've survived because they've supported me."