ANEOHE BAY, HI - DECEMBER 25: (AFP OUT) Ffirst lady Michelle Obama lisens as her husband U.S. President Barack Obama speaks during their annual trip to meet current and retired members of the U.S. military and their families as they eat a Christmas Day meal in the Anderson Hall mess hall at Marine Corps Base Hawaii on December 25, 2013 in Kaneohe Bay, Hawaii The first family will be vacationing in the Hawaiian Islands until January 5, 2013. (Kent Nishimura-Pool/Getty Images)
Michelle Obama, who turns 50 on Friday, is only just starting to build her legacy.
Presidential historians expect her commitment to fighting childhood obesity, supporting military families and encouraging good education and volunteer work to deepen in the next couple of years, and anticipate she will fully devote herself to those issues after she and her family leave the White House.
"I will be in my early 50s when I leave here, and I have so much more that I should do," Obama recently said in an interview with People magazine. "I don't have the right to just sit on my talents or blessings. I've got to keep figuring out ways to have an impact - whether as a mother or as a professional or as a mentor to other kids."
The first lady is likely to continue promoting Let's Move, her fitness and wellness program, and Join Forces, which assists military families, plus return to the philanthropy work that she did before she became first lady. But she's unlikely to make a run for public office, experts say.
Robert Watson, a presidential historian and professor at Lynn University in Florida, expects the final year of President Obama's second term to be a big year for Michelle Obama.
"If history holds, I expect Mrs. Obama will enlarge in her role," he said, pointing to the fact that she already is making more of an effort to promote a good education than she did in the president's first term.
"She's going to assert herself. We're going to see more of the Ivy League-educated lawyer and former CEO," he said, adding that while presidents often have difficult second terms marred by sagging approval ratings or scandals, as was the case with Richard Nixon, Bill Clinton, George W. Bush, Ronald Reagan and Franklin Delano Roosevelt, first ladies "tend to spread their wings" during second terms.
This term and beyond, she could also continue to be the go-to public figure for health and fitness awareness, said Tom Hubbard, vice president for policy at the non-profit health policy institute NEHI.
"There's unquestionably been higher awareness of these issues amongst policymakers at the local level," he said. "Mrs. Obama has been the public face of that, and that's what may be the lasting legacy."
Obama has done a particularly good job emphasizing the need for more physical activity for communities who need it using scientific evidence.
"She's elevated health and wellness and specifically good nutrition and the need for daily physical activity higher on the radar screen of America, particularly in regards to kids, lower-income kids, minority kids and making this a leadership issues in the African-American community, which has disparate rates of chronic disease that can be tracked back to nutrition and physical activity needs," he said.
When the Obama family moves out of the White House in 2016, Michelle Obama is likely to set up a foundation for her causes, Watson said.
"I think she'll always be active in her community," said Myra Gutin, a professor at Rider University in New Jersey who has written two books on first ladies.
Obama, who hails from Chicago's South Side, has a rich history in her hometown: In the 1990s, she was assistant commissioner of planning and development in Chicago's City Hall before becoming the founding executive director of the Chicago chapter of Public Allies, a program that prepares youth for public service. Later, she developed the first community service program at University of Chicago and as vice president of community and external affairs for the University of Chicago Medical Center, she brought in an influx of volunteers.
"It's been suggested that she might run for the Senate from Illinois. I really don't see her doing that," Gutin said. "She could go back to the University of Chicago hospitals, if that was her want. I just don't see her running for elective office."
"I don't see Mrs. Obama getting into politics because she was a reluctant campaigner initially," he said. Instead, he said, it would make sense for the woman who planted the White House's largest vegetable garden as part of her push for healthy eating to continue embracing issues like wellness.
"I would imagine her playing a very strong and leading role in the Obama presidential library. I can see it having a heck of a garden," he said.
She may also steer clear of serving on boards because of the scrutiny that comes along with that - but fundraising is a safe bet.
"I couldn't imagine her practicing law, but you could see her going back and fundraising or supporting the University of Chicago and the medical center, things she was doing before," he said.
Obama did have one slip before becoming first lady: a February 2008 speech in Wisconsin in which she said, "For the first time in my adult lifetime, I'm really proud of my country," prompting critics to call her unpatriotic for months afterwards. But she learned from the mistake, Watson said, ultimately making her "one of the best" first ladies.
"She has not been a liability since the '08 campaign. She's been a huge asset," he said. "I think she's been effective with her mothering. In a way, I think she's been effective with everything. She's sort of that superwoman. She has the husband, the good marriage, the perfect kids. She had a good career. She's done it all, and she looks darn good for 50."