On September 28, Sina and her sons Jimmy, Johnny, Peter and Anthony stepped off a plane in Illinois.

That day came 15 years after the death of Sina’s husband – the boys’ American father – set them on an odyssey through the channels of US immigration law: first trying to secure acknowledgement of her sons’ citizenship, then attempting to secure permanent residency under an obscure process known as a “widow petition”.

The process began in 1998, with the untimely death of Sina’s husband. The two had met after he returned from the US – where he was granted citizenship after arriving a refugee – and married in 1990. At first, their marriage had been clandestine out of necessity, due to her husband’s then-unpopular political beliefs.

“He came here secretly,” she said, declining to name her husband due to the ongoing sensitivity of the matter. “He could not let anyone know that he came into Cambodia, so he could not register the marriage.”

In 1998, Sina’s husband contracted an intestinal parasite. It wasn’t until a month before his death that Sina even knew he was ill.

The years following her husband’s death were difficult for the family. Sina found work in Phnom Penh in 1999, and though she maintains that relatives “were happy to help us”, her eyes brimmed with tears as she talked about the new responsibilities that were heaped on her after the death of the family’s sole breadwinner.

Sina and her husband knew they wanted their children to be able to study in America, but at the time of her husband’s death, Sina didn’t even realise her children were citizens.

When she finally learned that her children could legally be considered American, she was informed at the embassy that it would be nearly impossible to establish with her husband long dead.

Wayne Weightman, the US-licensed immigration adviser who shepherded Sina’s petitions for the better part of seven years, said that at the time, the officials in charge were satisfied that the boys’ father was indeed the citizen they maintained he was.

Over the course of two years, Weightman set about proving that their father had spent at least five years in the States. He chased leads in the US, even enlisting the help of his own father back home, finally pleading with the US Social Security Administration.

“I called Social Security, and I found some guy, and I said, ‘This is your chance to help somebody. I just need the name so I can prove this stuff. Is he in there?’” Weightman recalled. “And they said ‘yes’.”

But the search had taken so long that the officers in charge of the case had left and been replaced, and their replacements were not as confident of the children’s paternity.

“So we went to the embassy, and they said, ‘Well, that’s all good, but it’s been so long … now we want DNA’,” he said. “We had a couple years pursuing one track, and then it turned into this whole other thing.”

Since Sina’s husband had been cremated, there was no DNA to give, and the investigation began anew.

This time, private investigators were brought in to track down children Sina’s husband had from a previous relationship in the US.

The family reached out to their previously unknown relatives, with the children even writing to their half-sister, asking her to provide DNA, but to no avail.

After years, it appeared the track had gone cold, but a change in US law then offered a glimmer of hope. Widows of US citizens have been able to petition for permanent residency in the States since 1990, but only if they met certain conditions.

For decades, these conditions – such as marriages lasting at least two years and petitions being filed within two years of a spouse’s death – had resulted in the deportation and rejection of hundreds of widows, a situation that came to be known as the “widow penalty”.

We had a couple years pursuing one track, then it turned into this whole other thing

The website of the advocacy group Surviving Spouses Against Deportation is full of stories of widows denied residency in the US after losing their US-citizen spouses.

In a particularly controversial case, the Japanese widow of a Marine sergeant was denied US residency after her husband was killed in Iraq just a month after their marriage, despite the fact that the two had a months-old US-citizen child. A congressman later introduced a “private bill” that would allow the widow and her child to remain in the US.

In 2009, however, US Senator Bill Nelson and Representative Jim McGovern introduced, and subsequently passed, a bill that amended the regulations behind the so-called widow penalty, namely the two-year minimum on marriages.

Although cases can still be held up in court, US immigration attorney and SSAD advocate Brent Renison said: “Overall, things have drastically improved with the new law.”

Figures from the Office of Immigration Statistics show that the number of widows admitted into the US had more than doubled between 2008 and 2012, to nearly 850, Renison said in an email.

“The numbers are still relatively low compared to overall immigrant admissions, but it does show that hundreds of widows each year are benefiting from the law allowing widows married less than two years to self-petition,” he said.

Luckily for Sina, the law also included a two-year grace period for widows who had not filed petitions within two years of their spouses’ deaths.

In 2011, just before the grace period expired, Weightman “saw the other avenue”. He and Sina changed gears, placing the boys’ citizenship petitions on hold, and throwing their energy into a new widow petition for Sina, filing it just within the deadline.

What followed was another two years of assuring immigration authorities that the family had support in the US, processing, lost mail, interviews and more than a little waiting.

Finally, on September 5, Sina got word that her petition had been accepted. After more than a decade, and thousands of dollars in fees, she and the boys would be free to travel to the US, where they would be granted green cards on arrival, and where her sons would be able to pursue their citizenship petition from within the US.

Despite the delays, Weightman maintains that the process is “navigable”.

“In Phnom Penh, the leadership is good,” he added, noting that it was an incredible stroke of luck to finally wind up with such an experienced case officer.

As for Sina, the experience hasn’t soured her on American bureaucracy, even after 11 years of grappling with it. To the contrary, it might be an improvement.

“I feel that they are good, because they follow the rules,” she said. “If they need anything, they tell me what they need and we will work together to find what I need to give to them.”

“In Cambodia it’s really hard,” she added. “They only think about money. If you don’t have money, you can’t do anything.”