A mother who was separated from her daughter after she and her husband made separate illegal crossings of the US border with their children has warned other migrants not to take the same risks.

Buena Ventura Martin Godinez was apart from her daughter for two months after the seven-year-old was taken across the US-Mexico border with her father, Pedro Godinez Aguilar.

He was convicted of the offense of illegal entry into the U.S. and awaits almost certain deportation at a jail in Atlanta.

The couple's daughter, Janne, seven, was in the custody of a child welfare agency in Michigan before being reunited with her mother in Miami.

Martin Godinez had made an illegal crossing of her own with their infant son two weeks before her husband and daughter.

As the grateful mother clutched her daughter on Sunday, she had a warning for other families.

'I would advise people to find another country to seek refuge ... because here the law is very tough. People don't have a heart,' she said with tears streaming down her cheeks.

'Your child is a treasure and to have them separated is very painful.'

Buena Ventura Martin-Godinez, left, hugs her daughter Janne in Miami International Airport. She brought her son

Buena Ventura Martin-Godinez, center, holds her son Pedro, left, as she is reunited with her daughter Janne, right, at Miami International Airport on Sunday

Martin was held for a week with her son in Arizona and Texas, at times sleeping on the concrete floor of a detention facility before she was released, she said.

She now wears a black monitoring device strapped to her ankle. She and her baby boy are with relatives in a town south of Miami.

The little girl was in the custody of a child welfare agency in Michigan, where Martin said her daughter made several tearful calls to her, asking when they'd be reunited.

It had been nearly two months since Martin Godinez had seen her daughter after the frightened young mother was separated from her family trying to illegally cross from Mexico into the U.S.

They've spoken tearfully by phone, but seeing her at a Miami airport on Sunday for the first time, Martin grabbed the child in a tight embrace, tears running down her cheeks during a reunion she feared may never happen.

'I feel very happy, now and to complete my joy I would like to have my husband released,' Martin said in Spanish as daughter Janne clutched a stuffed dog and blue balloons and played with her younger brother at baggage claim.

Martin brought her infant son from Mexico into the U.S illegally in May, fleeing what she said were threats from violent local gangsters demanding money in their hometown in northwestern Guatemala. Her husband followed two weeks later with the young girl.

But the family was caught by the Border Patrol and scattered about under President Donald Trump's zero-tolerance immigration policy forcing families to be separated when crossing the border illegally.

Her husband, Pedro Godinez Aguilar, was convicted of the misdemeanor offense of illegal entry into the U.S. and awaits almost certain deportation at a jail in Atlanta.

Martin was held for a week with her infant in Arizona and Texas, at times sleeping on the concrete floor of a detention facility before she was released, she said. She now wears a black monitoring device strapped to her ankle. She and her baby boy are with relatives in a town south of Miami.

The little girl was in the custody of a child welfare agency in Michigan, where Martin said her daughter made several tearful calls to her, asking when they'd be reunited.

The family is one of thousands who have tried to enter the U.S. illegally in recent weeks only to be caught up in the harsh reality of an immigration system that has never been as welcoming as many migrants hoped and has grown harsher under Trump, with the separation of parents from children being used as a means of discouraging illegal immigration.

More families are crossing the Southwest border from Guatemala than any other nation, with 29,278 families apprehended between October and the end of May.

Martin and her husband could easily have been apprehended under the previous administration, too, and would have faced a tough battle for asylum.

Buena Ventura Martin-Godinez, right, stands with her daughter Janne after being reunited at Miami International Airport. She advised other people considering breaking into the US illegally to think again

Martin has been getting some help from a local activist since she can't afford a lawyer. She's been working at a nearby plant nursery, earning $9 an hour. She puts her baby in day care as she presses her case for asylum. Pictured: The duo in Miami

But the father wouldn't have been prosecuted for a first-time crossing; he would likely have been briefly detained with his daughter and then released with a monitoring device while they battled their future out in court.

Their daughter also would not have been shipped alone across the country, leaving them desperately trying to get her back.

At Sunday's emotional reunion, the child's uncle Nicolas Godinez said his family had been sick with worry about her return. They'd heard unsubstantiated rumors the U.S. government was putting children like Janne up for adoption.

'To receive her is the most marvelous thing I could receive,' he said through tears.

Martin, who worked as a nurse in Guatemala, said she and her husband decided to leave San Juan Atitan because masked men were demanding extortion payments from her husband's small business selling internet access.

They traveled by bus to an area just south of the border in Arizona. She said they didn't use smugglers, though many Central Americans do and find themselves paying off the fees for years. Martin said she waded through knee-deep water with several other migrants and was immediately apprehended. Court records show her husband was caught in the same area May 16.

Martin has been getting some help from a local activist since she can't afford a lawyer. She's been working at a nearby plant nursery, earning $9 an hour. She puts her baby in day care as she presses her case for asylum.