Washington ? At 23, Mariana should be carefree. She is finishing up her undergraduate degree at the University of California, Los Angeles, and has been accepted to a master’s program at Harvard University’s education school.

But life is not so simple for Mariana, who insisted that only her first name be published because she is illegally in the United States and worries she could be deported to Guatemala, where she was born.

“I’m even afraid of eating an apple in the library because I’m afraid of getting caught,” she said.

Mariana also worries about how she will pay her tuition and what kind of work she will get after she completes school. “What happens next? Without a work permit, how do you exercise your degree?” she said during a recent interview.

Mariana is among an estimated 50,000 undocumented students in U.S. colleges today. These students would be among the people who would benefit from a part of an immigration bill that the Senate plans to resume work on this week.

Children born in the United States to undocumented parents are granted citizenship automatically. A section of the new legislation deals with illegal immigrants who came to the U.S. as children. They would gain temporary legal status when they graduate from high school as long as they agreed to enroll in college or enlist in the military.

They would be put on a fast, three-year path toward getting their permanent resident status and their green cards. While waiting for that, the students would be eligible for federal student loans and could work legally – options not available to them now.

The overall bill would help roughly 12 million illegal immigrants. For most, it would take a minimum of eight years to get a green card. The larger group also would have to pay fines that would not be imposed on the high-school graduates who came to the U.S. as kids.

In all, about 1 million people now in the country illegally could potentially benefit from the provision aimed at children. Those include students currently in elementary and secondary schools. Current law allows children in the U.S. illegally to get a free K-12 education. They can go to most colleges if they can pay their way.

In Kansas, illegal immigrants are allowed to enroll in state universities and pay in-state tuition.

The immigrants who would benefit from the provision must have been age 15 or younger when they were brought to the U.S. and must have arrived before January of this year. People older than 30 when the law is enacted would not benefit.

One of the most vocal student advocates is Marie Gonzalez, a 21-year-old junior at Westminster College in Missouri. She has made numerous trips to Washington to tell her story.

Her parents were deported to Costa Rica two years ago. Gonzalez, whose deportation was deferred, said she could be sent back next year.

She said saying goodbye to her parents was awful. “There’s no words to describe it. It’s been absolutely terrible. I’m an only child. They’re my best friends,” she said.