The winding Rio Grande river is the natural dividing line between the U.S. and Mexico in southern Texas.

Yvette Gaytan’s family has owned land on the border's edge for generations. Her kids fish along the river banks in Starr County.

The Trump administration has asked to use Gaytan’s land to build sections of the wall approved in the newly passed budget.

“I’m not looking to sell. I’m not looking to move,” she told ABC News. “My father helped build this house with his own two hands.”

Yvette Gatan's home.(Yvette Gatan) Yvette Gatan's home.

Not far from her home, President Donald Trump’s long-promised southern border wall continues to be a work in progress. Crews have now started preparing to build the first new miles. Further east, old barriers have been replaced with new ones.

Trump declared a national emergency last week to divert money from the Department of Defense. His battle with Congress, which resulted in the longest government shutdown in American history, left him with fewer funds to build the wall in places like Starr County.

Rio Grande river in Starr County, Texas(Yvette Gatan) Rio Grande river in Starr County, Texas

The nonprofit group Public Citizen, which represents Gaytan and other residents in the area and filed its lawsuit last week, argues that using the national emergency as a way to fund the wall is entirely unconstitutional.

“We’re at the very beginning of what’s probably going to be a long, drawn-out process,” said Public Citizen lawyer Michael Kirkpatrick.

In order to stop the construction, Kirkpatrick will have to wait for the Trump administration to figure out how it will fund the planned sections of the wall. But he says it's clear that any wall would hurt all of his clients.

The Trump administration has plans to build as many as 12 miles of new border wall in Starr County. It’s a massive steel fence design, 20 to 30 feet high. U.S. Customs and Border Protection is involved in a variety of legal disputes over these projects.

Rio Grande river in Starr County, Texas(Yvette Gatan) Rio Grande river in Starr County, Texas

In the meantime, Gaytan has been forced to confront the possibility of leaving the home passed down from her late parents. She understands the need for more border security and she’s not opposed to it.

“Put more people on the ground, put boots to the ground,” she said.

But from her land overlooking Mexico, she doesn’t see a national emergency, and leaving her family’s legacy behind would be a devastating outcome, she says, adding, "I’m not going to go down without a fight.”