Jill assumed the role of second lady in 2009 when her husband became Barack Obama's vice president
Jill Biden is no stranger to the glare of the political spotlight. Her husband has been a Washington insider since they wed in 1977, and she was America's second lady for eight years.
But if Joe Biden wins the White House, his 69-year-old wife will have the opportunity to push the role of first lady into the 21st century -- by keeping her full-time job as a professor.
"Most American women have both a work life and a family life, but first ladies have never been allowed to do so," said Katherine Jellison, a history professor at Ohio University.
"Maybe the time has come, however, when more Americans will feel comfortable with a first lady who isn't on-call at the White House 24/7."
Of course, Biden for years has been a trusted advisor to her husband, eight years her senior.
If he defeats President Donald Trump at the polls, she is expected as first lady to work on education issues and relaunch Joining Forces, a mission to rally around military families that she and Michelle Obama started in 2011.
But she is also a teacher, a mother, a grandmother and the rock that kept Biden going after tragedy struck nearly five decades ago.
'Damn tough and loyal'
In 1972, Joe Biden faced the unthinkable -- his young wife and daughter were killed in a car crash, and he was left alone to raise his two young sons, both injured in the accident.
Enter Jill Jacobs, who was born in 1951 and grew up in the suburbs of Philadelphia. Her father rose up the ranks in banking from teller to president, and her mom was a homemaker.
Jill was in the process of divorcing her first husband when she met Biden, a widower who was commuting daily from Delaware to Washington, where he served as a US senator.
The couple wed in 1977, and she became "Mom" to his sons Hunter and Beau. The Bidens have a daughter, Ashley, who was born in 1981.
While raising her family, Biden also earned two Master's degrees. She would eventually earn a doctorate in education, and now teaches at Northern Virginia Community College.
Since then, the couple has been through two failed presidential runs, his eight years as vice president and the death of Beau Biden after a battle with cancer.
"She put us back together," Biden said in a video shown in August during the Democratic National Convention, as he described Jill's impact on the tragedy-scarred family.
"She is so damn tough and loyal."
'Small acts of compassion'
Biden assumed the role of second lady in 2009 when her husband became Barack Obama's vice president, participating in high-profile events with first lady Michelle and developing a comfortable public speaking style.
And now, throughout her husband's third race for the White House, Biden has been one of his most effective and forceful surrogates.
She has campaigned tirelessly throughout her husband's run, crisscrossing early voting states Iowa and New Hampshire and battlegrounds such as Florida and Michigan in the home stretch, often at smaller events.
She often presents her husband as the candidate who best appeals not only to moderate Democrats, but also to independents and Republicans disappointed with Trump.
In March, she found herself in the role of protector at an event in Los Angeles, when she dramatically fended off two protesters who lunged at her husband on stage.
"We're OK," she said reassuringly.
In her convention speech from a classroom at a Wilmington high school where she taught English in the 1990s, she vouched for her husband's character, capabilities and heart.
"How do you make a broken family whole?" she said of Biden's persistence through adversity, a quality she believes connects him with millions of American families suffering through the pandemic, mass layoffs and racial tensions.
"The same way you make a nation whole," she added. "With love and understanding -- and with small acts of compassion. With bravery. With unwavering faith."