The New Zealand mother detained in an immigration facility in the state of Texas in the United States is safely back at her home in Washington.

Sarah Shaw and her 6-year-old son Isaac were detained at the Canadian border more than three weeks ago because she mistakenly tried to leave and re-enter the United States without both parts of her visa approved.

She was returning from putting her two other children on a flight to New Zealand from Vancouver.

A GoFundMe page set up by family friend Victoria Besancon says “Thanks to all of your support and advocating Sarah and her son have been released!

“While her lawyer’s words were ‘the war is not over’ and there are still legal battles to be had, this portion has been won!

“Thank you to everyone who supported, donated and reached out. We will continue to update the story as it unfolds. But they are home safe and sound.

“Please be praying for the next legal steps, and for a peaceful reintroduction to daily life for the Shaw family!”

A friend who told RNZ of her release said Shaw will give details of her experience in ICE.

On July 24, Shaw drove her two eldest children, Grace, 11, and Seth, 9, to the airport in Vancouver for a direct flight to New Zealand to visit their grandparents.

Isaac didn’t go on the trip because he wasn’t old enough to fly unaccompanied.

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After leaving Vancouver, when Shaw and Isaac tried to cross the border to return home, they were “forcibly detained”.

The Washington Federation of State Employees (WFSE) said Shaw and her son were held at the Dilley Immigration Processing Centre in Dilley, Texas.

Shaw’s lawyer, Minda Thorward, told local media the mother had a temporary immigration document that allowed her to travel and re-enter the US, but there was an “administrative error” with it.

When speaking to the media before Shaw’s release, Besancon said family and friends were desperately pleading for good news.

“As a mother, when you just imagine your child sitting essentially in a prison for something she shouldn’t be imprisoned for and you think about your 6-year-old grandchild just sitting there locked up.

“They don’t even have their normal clothes. They’re not allowed to wear their own underwear. They’re in these uniforms. They’re the only people in the entire facility that speak English.

“Not only are they detained, but they’re kind of in a very strange sort of social isolation. She’s absolutely terrified.”

Besancon has been able to speak with Shaw in a controlled capacity because Shaw signed a privacy release between herself, Besancon and her lawyer.

Besancon told RNZ that the conditions in the centre where Shaw and her son were being held were “very similar to a prison”.

More than US$56,000 ($94,500) has been raised in a GoFundMe set up for the family.

- Additional reporting by NZ Herald