SIMSBURY, Conn. — This tax season is Alaina Vermilya’s second year as a tax preparer, and she’s worked to become adept at sorting through clients’ documents, working through extensive questionnaires and scoring the biggest refund possible.

Vermilya, a trained and certified tax professional, is also 17.

Her work is rewarding, she said, “just knowing that the time I’m dedicating ... continues to impact the clients for months.”

Vermilya is a senior at The Ethel Walker School, a private all-girls school in Simsbury.

She and a group of fellow students are currently hosting the school’s fourth annual tax clinic, operating a Hartford location of the nationwide and IRS-endorsed Volunteer Income Tax Assistance program.

Through the program, individuals and families making up to $56,000 per year can receive free help preparing their tax returns.

Besides Walker, there are other high schools in the state that send teen tax preparers to volunteer sites. Laura O’Keefe, from program partner The Village, listed Manchester High School, Stafford High School and Tourtellotte Memorial High School off the top of her head.

Of the examples O’Keefe listed, however, Walker is the only all-girls school.

Over the last three years, the Walker tax preparers have found a total of $642,000 in returns, according to school spokesperson Michelle Helmin. She added the site’s average return last year was $2,454, which can be especially impactful for low-income individuals and families who otherwise may have unknowingly left money on the table.

The clinic provides a necessary service to clients — Walker Head of School Meera Viswanathan noted that “people are entitled to this” — but it also empowers the teen tax preparers.

Sorting through a stranger’s personal and financial documents “requires deep tact and respect,” Viswanathan said. It also forces the girls to take control and try their best, even if they’re nervous.

Viswanathan said it’s especially crucial for girls to learn this mindset, as girls tend to think they must either do something perfectly or not do it at all.

She doesn’t want her students leaving Walker with that outlook.

“My dream is that girls neither fly below the radar ... nor aim so high that they’re paralyzed,” Vis-wanathan said.

Not all of the Walker students can be tax preparers, though. Under IRS rules, volunteer preparers must be at least 16 years old. The Walker staff has younger students assist the clinic in other ways.

When clients walk into the Walker’s tax assistance site, they’re first met by a group of greeters, often first-year students or sophomores, who welcome them and make sure they brought all of the necessary documents.

Then, each individual client or family is assigned to a pair of IRS-certified tax preparers.

The preparer pair then works through each client’s tax forms, spending an average of about 45 minutes with each client, while school officials and certified public accountants stand by to answer any questions.

Some of the students also double as translators when needed. Ana Hunt, 16, is doing both intake and Spanish translation this year. Hayley Bravin, 19, is both a tax preparer and an ASL translator.

Bravin and her tax preparer partner, 16-year-old Kate Weiss, finished their first tax return of the year last weekend. It took about two hours, but afterward both girls were pleased with their work.

“It felt good for her and, in turn, it felt good for us,” Weiss said.