Since leaving the White House, Melania Trump’s world has gotten smaller.

Just how she likes it.

Cloistered behind the gates of her three homes, she sticks to a small circle — her son, her elderly parents and a handful of old friends. She visits her hairdressers, consults with Hervé Pierre, her longtime stylist, and sometimes meets her husband for Friday night dinner at their clubs. But her most ardent pursuit is a personal campaign: helping her son, Barron, 17, with his college search.

What she has not done, despite invitations from her husband, is appear on the campaign trail. Nor has she been at his side for any of his court appearances.

These are the days of Melania Trump, former first lady, current campaign spouse and wife to one of the most divisive figures in American public life. Unlike her predecessors, there are no plans for a speaking tour, a book or a major expansion of her charitable efforts, most of which, people close to the Trumps say, are not fully visible to the public. In her post-presidential life, Mrs. Trump wants what she could not get in the White House: a sense of privacy.

Those efforts to retreat from public life have been complicated by her husband, who has turned her once again into a candidate’s spouse. As Donald J. Trump faces a possible third indictment, she has remained steadfastly silent about his increasing legal peril.

While she supports his presidential bid, Mrs. Trump has not appeared on the trail since Mr. Trump announced his campaign in November and did not utter a public word about his effort until May, when she endorsed him in an interview with Fox News Digital.

“He has my support, and we look forward to restoring hope for the future and leading America with love and strength,” she said.

Her absence is a striking difference from the start of the first Trump campaign, when Mrs. Trump, wearing a white strapless dress, descended the golden escalator in front of her husband at his campaign kickoff at Trump Tower.

Mrs. Trump remains in touch and friendly with a small group of people from her time in the White House, including the designer Rachel Roy and Hilary Geary Ross, the prominent Palm Beach networker and wife of Wilbur L. Ross, the president’s former commerce secretary. She remains especially close with her parents, who have an apartment at Trump Tower in Manhattan and have been spotted at Trump events at Mar-a-Lago, the Trumps’ private club and residence.

“From her point of view and her friends’ point of view, she’s been through a lot and she’s come out a strong independent woman,” said R. Couri Hay, a publicist, who was an acquaintance of Mrs. Trump’s in New York before she headed to Washington. “She’s learned how to close the door and close the shutters and remain private. We don’t see a lot, we don’t hear a lot.”

Mrs. Trump declined an interview request. This account is based on a dozen interviews with associates, campaign aides and friends, most of whom spoke on the condition of anonymity because they were not authorized to discuss the private details of her life.

People close to the family say Mrs. Trump’s lack of public support should not be confused with disapproval or indifference. She remains defensive of her husband, sharing his belief that their family has been unfairly attacked. Deeply distrustful of the mainstream media, she is an avid reader of the Daily Mail online, tracking Mr. Trump’s coverage in the conservative British tabloid.

Mrs. Trump is particularly skeptical of the case by E. Jean Carroll, who won $5 million in damages in a trial accusing Mr. Trump of sexual abuse in the 1990s and defamation after he left the White House, according to two people familiar with her remarks. When Mrs. Trump saw coverage of her husband’s deposition in the case, she was livid at his legal team for failing to do more to raise objections. She has also privately questioned why Ms. Carroll could not recall the precise date of the alleged assault.

Still, Mrs. Trump believes that despite the legal peril, Mr. Trump could return to the White House next year. In private, she has expressed curiosity about Casey DeSantis, the wife of Mr. Trump’s chief rival, Gov. Ron DeSantis of Florida. Ms. DeSantis is a close adviser to her husband and a regular presence at his events, and she has begun to campaign for him on her own. In one of her rare interviews, Mrs. Trump mused to Fox News about having a second chance at being first lady, saying she would “prioritize the well-being and development of children” if she reprised the role.

But she has not yet prioritized campaigning. Although she has expressed willingness to do events for her husband next year, she has so far refused his requests to join him on the stump.

“I don’t think it’s going to be anything like what we’ve seen with Casey DeSantis,” said Stephanie Grisham, a former Trump aide who quit on Jan. 6. “She’s not going to be throwing on jeans and walking in parades.”

Kellyanne Conway, a longtime Trump adviser who is also close with Mrs. Trump, said the former first lady was “all in” on her husband’s candidacy and remained his “most trusted and most transparent adviser.” Both Trumps, she said, have privately discussed “priorities” for a second term.

“I know few people as comfortable in their skin as Melania Trump,” said Ms. Conway, who is not working for the campaign. “She knows who she is and keeps her priorities in check. Melania keeps them guessing, and they keep guessing wrong.”

That air of mystery extends to the gated communities of her husband’s clubs. In Palm Beach, Mrs. Trump is not a part of the social circuit, said Lore Smith, a longtime Palm Beach real estate agent who is a frequent visitor to the club.

Unlike her modern predecessors, who attended barre or spinning classes, Mrs. Trump isn’t seen at the fitness center and isn’t known to have a trainer, according to other club regulars and former aides. She has long been a fan of days spent at the spa, but she is almost never spotted outside at the pool at either Mar-a-Lago or Bedminster, Mr. Trump’s golf resort in New Jersey. Occasionally, she makes brief appearances at charity functions at Mar-a-Lago with her husband.

“They very much keep to themselves behind the confines of Mar-a-Lago,” Ms. Smith said.

Mrs. Trump remains closely involved with Barron’s education. He is enrolled in a private school in West Palm Beach and is beginning to look at colleges in New York.

Mrs. Trump is said to prefer the city to Mar-a-Lago or Bedminster. She has been spotted going to her hairdresser and entering and exiting Trump Tower, which she does through a special side entrance and a private elevator.

Outside the family residences, Mrs. Trump’s public schedule has been limited. She has done a handful of events, including collecting $500,000 in fees last year from the Log Cabin Republicans, a conservative group that supports L.G.B.T. rights, and Fix California, an elections organization founded by Richard Grenell, a former senior Trump administration official. Mr. Grenell declined to comment on her appearance at the events.

In February 2022, Mrs. Trump started “Fostering the Future,” a scholarship program for foster children aging out of the system. A person familiar with the program, who spoke on the condition of anonymity, would not offer details or disclose how many scholarships have been awarded, saying only that it was “more than two.” No charity with the name Fostering the Future or Be Best is registered in Florida or New York.

Michael Weitzman, the first recipient of one of the scholarships, said he received the funding for four years at Oral Roberts University through a mentor, who knew a friend involved with the Trumps. “He asked if going to college was still a dream of mine,” said Mr. Weitzman, who spent his childhood living in 12 foster homes. “He said that he might know somebody really rich who might want to pay for me to go.”

He did not fill out any kind of application but a day after the mentor floated the idea, he received an email from Mrs. Trump’s public relations team asking if he would participate in a Fox News interview with the former first lady, her first since leaving the White House. The scholarship was announced during the May 2022 interview, with Mr. Weitzman participating over Zoom. Mr. Weitzman, 26, said he had not had any interactions Mrs. Trump since.

”I haven’t met her in person. I wondered often if I would and would love to,” he said. “I’m beyond grateful. There’s no reason that anybody should have done this for me.”

Mrs. Trump’s aides declined to discuss the details of her campaign plans, her charitable and business ventures and her views on her husband’s legal issues. Mr. Trump’s campaign declined to comment.

In many ways, Mrs. Trump’s post-White House life is an extension of her style as first lady.

From the start of her husband’s term, when she didn’t immediately move into the White House, Mrs. Trump often vacillated between two extremes: embracing her role or bucking all expectations associated with it.

One of her most memorable moments was made through a fashion statement. While returning from a visit to a Texas border town to meet detained migrant children, she wore a jacket emblazoned with the phrase, “I really don’t care. Do U?”

Much of her White House experience was marked by what people close to her described as disappointment and betrayal from friends, aides and even members of the Trump family. At times, her relationships with Ivanka Trump and Jared Kushner, Mr. Trump’s daughter and son-in-law, were strained, according to former aides. Since then, her former press secretary, Ms. Grisham, and a former aide and friend, Stephanie Winston Wolkoff, have written tell-all books depicting her as icy and disengaged from the role.

Those experiences pushed Mrs. Trump to retreat even further from the public, say people familiar with the family.

But that privacy may be hard to maintain under the scrutiny of a contested presidential primary and legal investigations.

Last week, Chris Christie criticized both Trumps for a $155,000 payment to Mrs. Trump from a super PAC aligned with her husband’s campaign. A representative for the super PAC said that Mrs. Trump was hired in 2021 for “design consulting,” including choosing tableware, arranging settings and picking floral arrangements.

“There’s grifting and then there’s Trump grifting,” Mr. Christie, the former New Jersey governor and most outspoken Trump critic in the 2024 Republican primary field, wrote on Twitter. “Undisputed champs.”

Most of her public profile, conducted largely through her social media accounts, is focused on selling a variety of digital trading cards. Her NFTs, or nonfungible tokens, include digital drawings of her eyes, a broad-brimmed hat worn during a state visit, White House Christmas ornaments and a blue rose intended to commemorate National Foster Care Month.

The majority of her tweets and Instagram posts directly promote the NFTs or a business called USA Memorabilia, which sells them. A day after Mr. Trump announced on his social media website Truth Social that he had received a target letter in the federal investigation into his efforts to thwart the transfer of power in 2020, Mrs. Trump’s only public comment was an announcement of a new “Man on the Moon” NFT collection.

A portion of her proceeds is donated, though her aides would not provide details about the amount given or specify the charity.

While first ladies often capitalize on the attendant fame, Mrs. Trump’s moneymaking venture is different from those of her predecessors, said Kate Andersen Brower, the author of “First Women: The Grace and Power of America’s Modern First Ladies.”

Michelle Obama was reportedly paid more than $60 million in a joint book deal with her husband, as well as commanding hundreds of thousands of dollars for speeches and signing a lucrative production deal with Netflix. Laura Bush and Hillary Clinton also sold their memoirs for millions. Their memoirs and paid speeches required the former first ladies to share some details about themselves, their views and their lives in the White House.

By simply selling images, Mrs. Trump reveals nothing.

That’s exactly how she likes it, Ms. Brower said.

“She’s the most obviously unknowable first lady,” she said of Mrs. Trump’s public persona. “There’s something radical about it. First ladies are expected to want to please people and I’m not sure she really cares.”

Maggie Haberman and Susan Beachy contributed reporting.