And as Capitol Hill finds itself at yet another logjam, this time over the issue of student loan interest rates, she's speaking out.
"Washington is kind of ridiculous," Sinema, D-Ariz., told the Washington Examiner. "They've taken an issue that's really a bread-and-butter issue, about families and preparing for the future, and turned it into a partisan issue. It's really disrespectful to students, frankly."
Congress' failure to act on the issue by July 1 meant that interest rates on federally subsidized student loans doubled from 3.4 percent to 6.8 percent.
With student debt already at record highs, the House in May passed a bill that would tie rates to financial markets. But last week a Senate proposal to freeze the interest rate at 3.4 percent for another year failed to draw enough support to clear a procedural hurdle, then lost all momentum when the Senate turned its attention to internal conflicts over the use of the filibuster.
Without progress on Capitol Hill, the change in rates will cost the average student an extra $2,600 over a decade, according to Congress' Joint Economic Committee. Students who borrow the maximum amount would pay $4,500 more in interest over the course of their loans.
Sinema, 37, has four college degrees and has taught at Arizona State University, the school she now represents, for the past 11 years. This fall, she will teach a graduate-level class on fundraising and grant writing for nonprofits. With 60,000 students on its main campus in Tempe and another 12,000 elsewhere in the Phoenix area, ASU is the largest public university in the country by enrollment.
Over a decade of teaching, Sinema found that students' primary concern has shifted from finding a suitable job to "how to pay their student loan debts ... [Students are] worried and nervous and scared about the future."
The Arizona Democrat introduced a bill, the Stability to Ensure the American Dream for Youth Act, that would put a four-year freeze on student loan interest rates at 3.4 percent. But even she acknowledges that the bill is unlikely to gain traction.
"I haven't really asked any Republicans to sign on," she said. "Shortly after I introduced the legislation, the issue got hyperpoliticized."
Instead, she is encouraging students in her district to share their student loan stories on social media to increase pressure on politicians to come to "a compromise in the middle."
But her own story is among the most compelling. Having grown up in poverty -- at one point living in a gas station without electricity or running water -- Sinema relied on Pell grants, scholarships and federal loans to earn a bachelor's degree, a master's degree, a law degree and a Ph.D.
Calling herself a "perennial student," she earned her bachelor's degree at the age of 18, having attended college classes while still in high school.
"There were government programs that helped me," she said.
The $50,000 in student debt the congresswoman owes is from federally subsidized loans, known as Stafford loans, that she took out while earning her law degree.
Sinema waves off suggestions that subsidized loans encourage students to work toward degrees that may not pay off in the job market.
"Access to education helps you financially in this country, but it also helps you become a better citizen," she said, citing herself as an example.
She isn't teaching full time, but she argues that her Ph.D in social work makes her a better member of Congress because it taught her to "think differently."