Dr. Jill Biden has been by Joe Biden's side since before his tenure as vice president, and even before his first run for president in 1987. In their 40-plus years of marriage, they've expanded their family, welcomed multiple grandchildren, and moved into the White House. They've also endured the painful tragedy of losing a son, Beau Biden, to brain cancer in 2015.

"She is so damn tough and loyal," the president-elect said about his wife last August.

Now, the longtime couple are heading back to the White House as Joe Biden defeated President Donald Trump in 2020 presidential election. All eyes may be on Joe for now, but don't forget about Jill, a longtime educator, proud military mom, and "prankster" grandmother. After her husband was elected, she responded to the victory with a sweet photo, writing, "He will be a President for all of our families."

Speaking at the 2020 Democratic National Convention, she said that Joe and Vice President-elect Kamala Harris "will work as hard as you do every day to make this nation better. And if I have the honor of serving as your First Lady, I will too."

Here's are the basics on Dr. Biden.

She's a teacher.

Jill has been an educator for decades. She's a longtime professor at Northern Virginia Community College, where she teaches English. She started working at the college in 2009, just before President Barack Obama's first inauguration, per The L.A. Times.

Before that, she taught at a number of public schools in Delaware, including Delaware Technical Community College and Wilmington's Brandywine High School, where she delivered her speech for the 2020 DNC.

"I have always loved the sounds of a classroom, the quiet that sparks with possibility just before students shuffle in, the murmur of ideas bouncing back and forth as we explore the world together, the laughter and tiny moments of surprise you find in materials you've taught a million times," she said in the televised address. "When I taught English here at Brandywine High School, I would spend my summer preparing for the school year about to start filled with anticipation."

In 2007, she earned her doctorate in education from the University of Delaware.

She plans to continue teaching if she becomes First Lady.

"I would love to," she told CBS in August. "If we get to the White House, I'm gonna continue to teach. It's important, and I want people to value teachers and know their contributions, and lift up the profession."

Jill did the same thing when she was Second Lady, teaching English full time at Northern Virginia Community College. "I teach a lot of immigrants, and refugees," she told CBS of her students. "I love their stories, I love who they are as people, and I love the fact that I can help them on their path to success."

This year, she took a break from teaching for the first time since 1981 to assist her husband on the campaign trail, according to The Washington Post.

She's proud of her doctorate.

After a December 2020 Wall Street Journal op-ed called on the future First Lady to remove "Dr." from her title, many responded by defending her academic and career accomplishments. (Michelle Obama and Bernice King were among those who stood by her.) Dr. Biden eventually responded to the piece herself, calling it "such a surprise" and thanking those who spoke out to support her.

"One of the things I'm most proud of is my doctorate," she said in an interview with Stephen Colbert. "I mean, I worked so hard for it. You know, Joe came when I defended my thesis."

She had also previously written in her memoir, as Colbert pointed out, "The role I have always felt most at home in is Dr. Biden."

She championed military families and community colleges as Second Lady.

"Having had a father in the military, having a son [Beau] deployed in Iraq, I saw the need to support military families," Jill said in her DNC intro video. Her achievements in the White House included the Joining Forces initiative with First Lady Michelle Obama, which works to "ensure that service members, veterans, and their families have the tools they need to succeed throughout their lives."

As a longtime educator, she's also vocal about the importance of community colleges, calling them "one of America’s best-kept secrets." According to the White House website, she hosted the first White House Summit on Community Colleges with President Obama in 2010 and she traveled the country for a Community College to Career bus tour in 2012.

She also prioritized breast cancer research after founding the Biden Breast Health Initiative in Delaware in 1993.

If she becomes First Lady, she plans to continue advocating for free community college tuition, funding for cancer research, and support for military families, CBS reported.

She was born in New Jersey.

Dr. Jill Biden was born Jill Jacobs in 1951 in Hammonton, New Jersey, where her parents were raised and her grandparents lived. However, she grew up in Willow Grove, Pennsylvania, with four younger sisters. She attended Upper Moreland High School, then received her bachelor's degree in English at the University of Delaware. She obtained two master's degrees before earning her doctorate: one in English from Villanova University in 1987, the other in reading from West Chester University in 1981.

She married Joe in 1977.

Jill recalled on Twitter that she first "met" her now husband when he gave her a random phone call. "'How did you get this number?' Those were the first words I spoke to Joe when he called me out of the blue on a Saturday in 1975," she wrote.

Of their first date, she said in an interview, "I was a senior, and I had been dating guys in jeans and clogs and T-shirts, he came to the door and he had a sport coat and loafers, and I thought, 'God, this is never going to work, not in a million years. He was nine years older than I am! But we went out to see A Man and a Woman at the movie theater in Philadelphia, and we really hit it off."

Joe proposed five times before Jill said yes, he recalled in a DNC video. Jill was hesitant because she wanted to make sure that Joe's two sons, Beau and Hunter Biden, were okay with it. After she finally said yes, she and Joe said "I do" on June 17, 1977, at the United Nations Chapel in New York City. They welcomed a daughter, Ashley Biden, together in 1981.

Before tying the knot with Joe, Jill was previously married to Bill Stevenson, per BBC. The former vice president was also previously married to Neilia Hunter, who passed away with their daughter, Naomi Biden, in a car accident in 1972. They welcomed sons Beau and Hunter together, but Jill embraced and raised them as her own. "Neilia would always be Mommy, but Jill was Mom," Joe wrote in his 2007 memoir, Promises to Keep, noting that his sons didn't refer to Jill as their "stepmom."

She has a sense of humor.

"I would say she's not your average grandmother," Naomi Biden, one of Joe and Jill's granddaughters, said in a DNC video. "She's the grandmother that wakes you up at, what was it, 5 a.m. on Christmas Eve to go SoulCycle-ing.

"She's a prankster, she's very mischievous. When she goes on a run, sometimes she'll find, like, a dead snake and she'll pick it up and put it in a bag, and she'll use it to scare someone."

This story has been updated.