A Gallup poll released last month found the first lady's favorability ratings topped those for her husband, Bill and Hillary Clinton, George W. Bush, Sarah Palin and a host of other figures in the public eye.
But Mrs. Obama has not been immune to criticism.
Early in her husband's presidency, the first lady was skewered for wearing pricey sneakers by French design house Lanvin when she volunteered at a food bank. (The shoes can go for upwards of $500.)
And the first couple caught criticism when the president and Mrs. Obama flew Air Force One to New York last year for a date.
"If I weren't president, I would be happy to catch the shuttle with my wife to take her to a Broadway show, " Barack Obama groused months later. "The notion that I just couldn't take my wife out on a date without it being a political issue was not something I was happy about."
There also was a bit of grumbling last year when Obama ended a four-nation trip with some Paris sightseeing with his wife and their two daughters, including a stop at Notre-Dame Cathedral. The girls and the first lady lingered in the city after the president left for home, visiting the Eiffel Tower and other spots.
White House Press Secretary Robert Gibbs last week tried to dismiss questions about the first lady's trip by saying, "She is a private citizen and is the mother of a daughter on a private trip."
But fair or not, any action by a modern president — or his wife — is sure to be viewed through a political prism, said McBride, who was Mrs. Bush's chief of staff.
"Everything you do when you're in a political environment has to be weighed," she said. "It's just the reality of being a public person."
Mrs. Obama isn't the first first lady to leave her husband home and go on vacation overseas.
Hillary Rodham Clinton and daughter Chelsea traveled by prop plane, land rover and rowboat to take a weekend break at a jungle lodge in Nepal during a mother-daughter tour of South Asia in 1995. And when the first lady and her daughter clambered atop a 10-foot-tall elephant to go on safari, the entourage include Secret Service agents packed onto another pachyderm.
The fact that the personal weekend retreat was sandwiched in the middle of a whirlwind 12-day official trip across South Asia may have helped avoid stirring criticism.
When Jacqueline Kennedy and her daughter Caroline spent three weeks at a seaside villa in Italy in 1962, the biggest controversy seemed to be over the first lady's decision to take Caroline water skiing. A London tabloid, which displayed a photo of Kennedy holding her crying daughter's head above water after a spill, proclaimed the outing "madness." A Colorado minister criticized her for appearing in public in a bathing suit and staying out until the early morning hours "while away from the U.S. and her husband."