Melania Trump's move to distance herself from US President Donald Trump's criticism of NBA superstar LeBron James is the latest in her quiet but seemingly concerted effort to create space between herself and her husband, careful not to criticise him directly while making clear she does not agree with him.

She made her disappointment with the Trump administration's policy on forced family separations along the US-Mexico border known on Twitter and has twice visited displaced children, a step not taken by the president.

She vanished from public sight amid renewed scrutiny of Trump's alleged affair with porn star Stormy Daniels. And her spokeswoman has said the first lady watches whatever TV news station she wants, even ones criticised by her husband.

Melania Trump's moves to chart her own path are drawing attention and, for some, mark her as an unlikely symbol of resistance. But to others her acts are empty and do nothing to absolve her connection with Trump and his policies.

Her response to Trump's criticism of James, one the US's most prominent African-American men, illustrates a path she is more frequently taking.

Trump derided the intelligence of James after watching an interview the Ohio native gave CNN in which he criticised the president.

The media has long been denounced by Trump but the attack on James resembled, for some, a racial dog whistle.

Stephanie Grisham, the first lady's spokeswoman, quickly distanced the first lady from the criticism with a statement saying it appeared James was "working to do good things on behalf of our next generation" and that the first lady would be open to visiting his new Akron school for at-risk children.

Children and their fate was also at the heart of Melania Trump's previous break from the president in June when Grisham issued a statement saying the first lady: "hates to see children separated from their families".

She said the US needed to be one that "governs with heart" and then visited children at the border twice, with the first visit overshadowed by a curious choice to wear a jacket that read "I REALLY DON'T CARE, DO U?"

The president declared the jacket was about the "Fake News Media." Grisham said: "It's a jacket. There was no hidden message."

But the East Wing of the White House, where Melania Trump's office is located, has made a point, at times, to make sure that it is viewed differently than the other side of the executive mansion.

She has also been unafraid to smack down some of the president's closest allies.

Earlier this year, after Trump's laywer Rudy Giuliani said that Melania believed her husband about Daniels, an East Wing statement said: "I don't believe Mrs. Trump has ever discussed her thoughts on anything with Mr. Giuliani."

Some observers believe that her motives are calculated.

"It's a wink-wink strategy," said former political adviser Tobe Berkovitz.

"It obviously helps the first lady because it shows her as thoughtful and independent, but it also helps him keep something he wants in the news."

Australian Associated Press