President Donald Trump has three siblings, one of whom joins her brother in the realm of politics.

Maryanne Trump Barry, Trump's 81-year-old sister, has a law degree from Hofstra University and served as a federal judge.

In 1999, President Bill Clinton nominated her to the US Court of Appeals for the Third Circuit.

She took an inactive status in 2017.

Americans may feel like they know a lot about the Trump family. Eldest daughter Ivanka, first lady Melania, and eldest son Donald Jr. are in the public eye on nearly a daily basis.

But some people may not know President Donald Trump has three living siblings — including two older sisters, Maryanne Trump Barry and Elizabeth Trump Grau, and a younger brother, Robert Trump. His older brother, Frederick Trump Jr., died in 1981.

Part of the Trump family. Maryanne Trump Barry sits on the right. Charles Rex Arbogast/Associated Press

The eldest sibling is Maryanne Trump Barry, 81, a senior judge on the US Court of Appeals for the Third Circuit. She took an inactive status in 2017.

Barry has a law degree from Hofstra University and, in 1983, was nominated by former president Ronald Reagan as the District Judge for New Jersey (Newark). She held the position for 16 years. Then, in 1999, President Bill Clinton nominated her to serve on the US Court of Appeals for the Third Circuit.

At a rare public appearance — a 2011 commencement speech at Fairfield University, in Connecticut — Barry spoke about entering the male-dominated legal field early in her career. The Washington Post reported her saying: "My first job out of law school was as one of two women assistant US attorneys in an office of 63 US attorneys, and the first woman to do criminal work appearing only before male judges. Scared? Every day of my life."

Barry is reportedly very close with the president. WNYC reported she served as a bridesmaid in his first wedding, gave him advice during a scandal involving Megyn Kelly, and, along with their other siblings, gave him money when he needed it in 1993 (which Trump later denied).

Neither of the siblings are sticklers for political correctness. In a 1992 speech, according to The Washington Post, Barry said:

"I stand second to none in condemning sexual harassment of women. But what is happening is that every sexy joke of long ago, every flirtation, is being recalled by some women and revised and reevaluated as sexual harassment. Many of these accusations are, in anybody's book, frivolous … Frivolous accusations reduce, if not eliminate, not only communication between men and women but any kind of playfulness and banter. Where has the laughter gone?"

From Left to Right: Vanessa Haydon, Donald Trump, Jr., Donald Trump, Melania Trump, Maryanne Trump Barry, Elizabeth Trump Grau, and James Grau. JASON SZENES/Associated Press

In her Fairfield commencement speech, Barry explained her definition of success, which is in opposition to her brother's focus on material wealth and business success:

"When I say success, I don't speak only of professional success. Success can be something as simple as the warm feeling one gets if you see a stranger that you sense to be lonely and smiling at that stranger and having that stranger return your smile; it can be bringing a child into the world and raising a child to be a good man or a good woman."

Over the years, she has also held stances on issues that run counter to the president's current agenda. For example, according to WNYC, she has taken positions viewed as supporting abortion rights, and has also expressed pro-immigrant views.

"Neither of my parents had English as a first language," she once said, according to WNYC. "My father’s father died when he was a teenager, and dad went to work to support his mother and two siblings as a carpenter and as a builder’s mule, hauling carts of lumber to construction sites when it was too icey for the mules to climb the hills."

As for her personal life, Barry's husband, John J. Barry, was an experienced trial and appellate lawyer who died in 2000, according to The New York Times.

She had one son, David Desmond, a former neuropsychologist who is now an author, with her first husband. Desmond was known in Palm Beach, Florida for his columns, which gently mocked the island's wealthy inhabitants, according to the Palm Beach Post.

Barry previously owned an oceanfront mansion next to Trump's Mar-a-Lago in Palm Beach, Florida, but sold it to her nephews, Eric Trump and Donald Trump Jr., in May for $18.5 million, according to the Los Angeles Times.

The two "New York power siblings" spoke to New York Magazine together, and Trump expressed pride that his older sister was a federal judge "one notch below the Supreme Court!"

Barry said she "knew better even as a child than to even attempt to compete with Donald," which Trump said was good because the two of them would have been "butting heads."

She said Trump showed his love after she had an operation.

"Donald came to the hospital every single day," she told NYMag. "Once would have been enough — the duty call. That's how love shows, when you go that extra yard."