For years she's been the intensely private scion of a family synonymous with American public life.
Now, in her appointment as US envoy to Japan, Caroline Kennedy is finally hitting the big stage.
The sole surviving child of assassinated president John F. Kennedy takes over the ambassador's residence in Tokyo at a time when Asia couldn't be more important to US foreign policy.
Washington has its eyes on a newly belligerent North Korea, rising rival power China, and, as always, its close alliance with Japan.
Even before she was named, many Japanese were excited at the prospect.
The government spokesman said her appointment "would deepen people's feeling of friendliness" to the United States, because the "late President Kennedy was a figure familiar to many Japanese."
For Caroline Kennedy, 55, a plum diplomatic appointment by a friendly Democratic president might hardly seem a surprise.
After all, Joseph Kennedy, her grandfather, was named just before World War II by Franklin Roosevelt to a controversial spell at the head of the embassy in London.
There's also a strong link between Caroline Kennedy and President Barack Obama, whom she helped burst from relative obscurity in 2008, when he was taking on the far more powerful Democrat Hillary Clinton for the party's presidential nomination.
In a New York Times column titled "A President Like My Father" Kennedy wrote of never having seen a president who matched up to the way people still talked about JFK.
Now, she said, "I believe I have found a man who could be that president."
There will inevitably be questions about Caroline Kennedy's suitability to the high-profile diplomatic job.
However, political appointees in ambassador's posts are common under both Democratic and Republican presidents, even if the practice sometimes backfires.
During his posting in wartime Britain, Joseph Kennedy became increasingly unpopular for what were seen as his defeatist views.
One member of parliament called him a "rich man, untrained in diplomacy, unlearned in history and politics."
Judging Caroline Kennedy's level of preparedness is difficult.
Wealthy, she graduated as a lawyer, but reportedly never practiced, and although she has penned numerous books, she has never played the celebrity.
While living on New York's exclusive Park Avenue, she reportedly uses the subway system and keeps her philanthropic work and support for public education out of the newspapers.
Indeed, for many Americans, Caroline Kennedy is frozen in time -- forever the adorable girl photographed riding her pony around the White House grounds or, tragically, attending her father's 1963 funeral at Arlington Cemetery.
For a time in late 2008 and early 2009, she toyed with the idea of running for the New York Democratic Senate seat vacated by Clinton when Clinton became Obama's first-term secretary of state.
But that foray into the hurly burly of politics in 2008 ended in humiliating retreat, with newspapers and opponents mocking Caroline Kennedy for lack of readiness and even an inability to speak coherently in interviews.
Diplomatic circles might suit her better and there's a plus: her boss, Secretary of State John Kerry, is another New England blue blood and was close to her uncle, the late senator Ted Kennedy.