The family stayed six months on a tourist visa, then slipped into the shadows. The family settled in Cheltenham, where a relative had earned U.S. citizenship, then moved to Springfield, Montgomery County.
The father found a job cleaning hotel rooms. The mother worked as a domestic. They still do that work.
Meanwhile, the children grew up as Americans. "I went to school, I played sports," says Fernanda. "My parents never sat me down and told me I was different. I thought I was like everyone else."
The three children did not know they were here illegally until Maria, the oldest, was 17, and tried to select classes at Penn State Abington. Unable to produce a Social Security number, she lost her offer of financial aid, and when she started calculating the cost of international tuition, she learned she was no longer welcome at any price.
I talked to Maria, now 25, this week in Chicago, where she is studying at Dominican University, having finished Montgomery County Community College with a nearly perfect 3.98 grade-point average.
She studies political science, a subject she understands firsthand, having been arrested in Georgia after donning a cap and gown and blocking the street to protest that state's immigration laws.
"I am hopeful, but we have to continue to hold the president accountable to make sure he follows through on his word," she said. "If [the administrative order] is implemented . . . not only would we not be deported to countries we barely remember, but we would also be able to work legally."
That would let her work to pay for her tuition. It's what Fernanda wants, too. She just finished her first semester on a merit scholarship at Eastern University, having transferred from Montco as well. She babysat to help her parents cover her costs.
Cesar, 21, wants to work, too. He dropped out of the community college after a few semesters, then walked dogs and tried construction. He says he's more mature now, after volunteering with an immigration-reform organization: "I know how privileged I'd be if I have a chance to go back to school."
The order Obama signed protects youths who arrived before age 16 and are younger than 30. They must have lived here five years, have attended high school, have not been convicted of a crime, and not pose a danger to public safety.
With the order, the president bypassed Senate Republicans, who in 2010 blocked passage of the DREAM Act, which would have provided a pathway to permanent residency or citizenship for young people like the Marroquins.
But there's no guarantee that they won't be deported when the order runs out in two years.
That's part of what troubles Fernanda. She's weary of the anxiety that weighs on her each time she drives her 1999 Ford Escort, knowing that if she's pulled over, she cannot produce a license.
She has responded by taking control of what she can, by stepping further into the limelight, speaking at rallies, protesting her life of limbo.
She says her prominence, and good legal counsel, will help protect her parents, too.
But she knows there's no guarantee of that, either.
Contact Daniel Rubin at email@example.com, 215-854-5917 or on Twitter @danielrubin