Melania and Donald Trump have a 'transactional marriage', it is claimed (Image: AFP/Getty Images)

Donald and Melania Trump have marked their 16th wedding anniversary amid speculation the former first lady could file for divorce.

The couple had plenty of frosty and awkward moments during their time in the White House, and it has been claimed they had a "transactional" marriage and slept in separate bedrooms.

A former White House aide claims the now former first lady was "counting every minute" until the end of twice-divorced Donald's presidency so she could leave him.

A top lawyer in New York has told the Mirror that Melania could get up to Sh5.5 billion ($50 million) and custody of the couple's 14-year-old son Barron if she divorces the disgraced property tycoon.

And bookmakers are taking bets on whether former fashion model Melania, 50, will file for divorce after leaving Washington as Joe Biden was sworn in as America's 46th president.

Sources told CNN last week that Melania slept in a large bedroom suite normally reserved for the president and their spouse.

"Donald Trump slept in his own bedroom, which was previously a study or den during other administrations," the source added.

 Donald and Melania with their son Barron, who is now 14, in August last year (Image: AFP via Getty Images)

Stephanie Winston Wolkoff, a former close friend and confidant of the ex-first lady, and author of the book Melania and Me, claimed the Trumps had separate bedrooms in the White House and "a transactional marriage".

She told the BBC in September last year: "I do believe it is a transactional marriage. Donald got arm candy, the Vogue cover (in February 2005) legitimised Melania which legitimised Donald as well, and Melania got two dynamic decades.

"She was a young model, she was striving, she didn't have the success yet. She met Donald, she married, she had a son, she became an American citizen and 10 years after that, she is the first lady of the United States.

"I do believe it was a magic moment, and I also believe it was a made-for-TV moment."

The couple's friends told the Washington Post in 2018 that the Trumps had separate daily routines.

Donald, now 74, would get out of bed at about 5.30am to begin watching cable TV news shows and tweeting.

Melania, who was born in Slovenia and is the former president's third wife, would wake up in her own bedroom a bit later and then get Barron ready for school.

In her 2018 book Unhinged, former Trump aide and The Apprentice contestant Omarosa Manigault-Newman claimed Melania was eager to divorce the president.

She wrote: “In my opinion, Melania is counting every minute until he is out of office and she can divorce him.”

 Melania was described as being 'checked out' in the weeks before leaving Washington (Image: Getty Images)

In the weeks leading up to the Trumps' exit from the White House, Melania was described as being "checked out" and just wanted to go home, sources told CNN.

She was "not sad to be leaving" Washington and the White House, the sources added.

Melania left with the worst favourability rating ever for a first lady, according to a CNN poll.

She had a favourable rating of 42 per cent versus a 47 per cent unfavourable rating.

The Trumps have moved back to Donald's Mar-a-Lago resort in Florida after Donald lost November's election and his bid for a second term.

It is claimed Melania renegotiated her prenuptial agreement before joining her husband in Washington in 2017.

Divorce experts suspect Melania would be in a much more favourable position now.

Donald's net worth declined to Sh275 billion ($2.5 billion) in 2020 from Sh341 billion ($3.1 billion) in 2019, and it might be even lower now due to hotel losses, Forbes reported.

Some reports claim Melania has a net worth of Sh5.5 billion ($50 million).

New York divorce lawyer Jacqueline Newman told the Mirror that Melania could get between Sh2.2 billion ( $20 million) and Sh5.5 billion ($50 million) in a divorce - far more than what Mr Trump's first two wives received.

Dad-of-five Donald's first marriage to Czech athlete and model Ivana Zelnickova officially ended in divorce in 1992 after the couple had three children, Donald Jr, Ivanka and Eric, all of whom have played public roles during their father's first term.

 Melania appeared to swerve a kiss from her husband during an event in August last year (Image: Getty Images)

A second marriage to actress Marla Maples in 1993 gave Donald another daughter named Tiffany. The couple separated in 1997 and divorced in 1999.

He had prenuptial agreements with both.

Ivana Trump, now 71, reportedly received Sh1.5 billion ($14 million), a mansion in Connecticut and an apartment in Trump Plaza as part of their divorce.

Marla, now 57, is reported to have received a Sh220 million ($2 million) settlement.

When Donald entered the White House in January 2017, his wife didn't join him until five months later.

Addressing speculation there was trouble in the marriage, she claimed she didn't want to interrupt then 10-year-old Barron's school year.

A book by Washington Post journalist Mary Jordan claims Melania delayed moving to the White House as leverage for renegotiating her prenup.

She needed time to cool off after details about her husband's alleged sexual indiscretions emerged.

She took that time to “amend her financial arrangement with Trump - what Melania referred to as ‘taking care of Barron'," according to The Art of Her Deal: The Untold Story of Melania Trump.

Her original prenup had not been very generous, and the new agreement ensured that Barron would not be shut out of the family business, the book claims.

During the 2016 campaign, Donald faced allegations of sexual assault and inappropriate sexual behaviour.

He has also been accused of having affairs with porn star Stormy Daniels and Playboy Playmate Karen McDougal.