Princess Charlene risks awkward run-in with Prince Albert's ex ...

Princess Charlene may be bracing herself for an awkward run-in with her husband's former mistress at the Monaco Grand Prix today.

The royal, 46, cut a glamorous figure in a navy oversized blazer as she joined her husband Prince Albert, 66, at the annual event in Monte Carlo this afternoon.

Earlier in the day, Nicole Coste - who dated Albert in secret for seven years and shares a son with the royal - posted on Instagram about attending the event.

The fashion designer, who met the royal while working as a flight attendant in 1997, shared a photo of herself dressed in a white trench coat and admiring the view from the venue.

Aligning herself with the Ferrari team, Nicole gushed: 'We are waiting for the victory of Charles Leclerc the the country’s child. Loving this jacket!'

Albert and Nicole's liaison became the best-kept secret among Monaco society. Although they both attended red carpet events and mixed with socialites and celebrities, the majority of Albert's subjects knew nothing of the relationship. 

Ahead of her 2011 wedding to Prince Albert, Charlene reportedly fell out with Nicole after she put her step-son Alexandre up in the Palace's staff wing.

While she has previously had a frosty relationship with Albert too - claiming he 'doesn't want to see his son' - she has recently lavished praise on the monarch - sharing a photo with him on his birthday with the caption: 'Happy birthday Albert.The world will recognise you as The Loyal, the Dignity, the KING'. 

In November 2022, she shared another shot of Albert with Alexandre and Jazmin in New York, New York, with the cheeky caption: ' Paternally king'. 

Earlier today, Princess Charlene has shared a sweet photo with her twins Prince Jacques and Princess Gabriella to mark Monaco's Mother's Day.

The royal, 46, opted for a double breasted suit jacket and slicked her hair back as she wrapped her arms around her two children.

'Happy Mother's Day,' she wrote.

Opting for a natural look, the mother-of-two looked a double of her daughter, who also wore a white jacket.

 Keeping with the smart theme, Prince Jacques wore a navy suit and tie.

Charlene meanwhile went for a natural make-up look, with a gentle eyeliner and light layer of foundation as she posed in the Monaco sunshine.

Meanwhile, Charlene's husband Prince Albert, 66, took a solo trip to the Monaco Grand Prix.

 The monarch opted for cream chinos and a navy check jacket and baseball cap.

Charlene and  Albert took their children for the opening of 'Monaco World' in Hamburg last month. 

 The family-of-four celebrated Monaco being added to the list of countries to appear in Miniature Wonderland, one of the most popular tourist attractions in Germany.

Charlene put her best fashion foot forward and donned a smart cream coat which she paired with black top. 

The former Olympic swimmer wrapped up warm with a onyx-coloured scarf, as temperatures in the German city were around nine degrees. 

Earlier this year, Albert was branded aa 'weak' leader who 'uses money to buy family peace', according to reports.

After questions were raised about the finances of the Monegasque Royal Family, journalists in the principality commented on the character of the 65-year-old premier. 

A dossier exposing the 'secret notebooks' of Claude Palmero, who was in charge of the Palace's finances for more than two decades and a confidant of Prince Albert until he was ousted last summer revealed startling claims about the royal family's finances - particularly those of Princess Charlene, 45.

The entries, which were shared with Le Monde newspaper in France, detailed extortionate costs spent by the Princess on things like the baptisms of her twins Jacques and Gabriella at around £600,000 and a general spending allowance of more than £1 million per year.

Speaking to Tatler, one of the journalists who broke the story has revealed Charlene has a 'crazy desire to spend money' which is granted by her husband to keep the peace.

They speculated that the Prince's disposition was due to experiencing 'a lot of' confrontation when his late father, Prince Rainier III, was alive. 

Elsewhere in the interview, Mr Davet reveals that the files he and his fellow reporter Fabrice Lhomme uncovered suggested Princess Charlene and her sister-in-law, Princess Caroline, are 'not friends'.

FEMAIL has contacted the Monegasque Palace for comment. 

Among the explosive claims uncovered in the dossier were allegations that Princess Charlene hired illegal immigrants on less than £90-per-day to work for her, despite her personal spending allowance skyrocketing to £1 million-per-year.

Mr Palmero's records suggested that 'illegal migrants' made up much of Charlene's full-time personal staff of eight - something the accountant expressed concerns about.

'Her Serene Highness the Princess makes people work for her who are not compliant,' Mr Palmero warned Prince Albert, also referring to 'a moonlighting Filipino woman who ties up dogs in the shower.' 

In a letter written in January 2017, he said another employee from the Philippines had been 'illegal for five years', despite solely being on a one-month tourist visa. 

'He gets paid 100 euros a day [£85] which is off the scale,' Mr Palmero wrote.

In December 2014, Charlene gave birth to Prince Jacques, and Princess Gabriella, and immediately placed them in the care of illegal immigrant nannies.

'Update on the hiring of nannies…We are completely illegal (even their tourist visa expired on January 7)' Mr Palmero wrote on January 15th of that year.

'They are not only in an illegal situation, but one entered with a false passport, Mr Palmero added.

Despite this, Mr Palmero released almost £600,000 to celebrate the children's birth and baptism. 

On one day alone in April 2016, Charlene asked for the equivalent of £66,000, and this was 'definitely too much,' said Mr Palmero, especially as she also planned to rent a second villa on Corsica. 

'Isn't that a lot?' asked the accountant, who was concerned that the Princess was taking money from funds that were 'undeclared' in terms of tax.

'These practices are dangerous,' Mr Palmero warned.

'They are not only in an illegal situation, but one entered with a false passport, Mr Palmero added.

The former chief royal wealth manager in the Mediterranean tax haven claims he desperately tried to rein in Charlene's 'dangerous' spending, and at one stage blocked the South African-born 45-year-old from taking on new staff. 

The books also allege that Albert spends millions every year from a secret French bank account to pay his former mistresses and love children - with Jazmin Grimaldi, 31, and Alexandre Coste-Grimaldi, 20, receiving allowances of £344,000 a year each.

This was while Charlene was pouring £826,000 into redecorating her holiday villa in Calvi, on the island of Corsica, along with £860,000 to decorate her office back in Monte Carlo.

Charlene was paying her personal chef the equivalent of £250-a-day from petty cash, said Mr Palmero, while her South African family were also receiving hundreds of thousands of pounds.

In February 2017, the accountant also released the equivalent of more than half-a-million pounds to pay off the Princess's overdraft.

In December 2019, an alarmed Mr Palmero noted that Charlene had spent 'around 15 million euros [£13m]', over eight years, despite her allowance being '7.5 million euros' [£6.4m]

This was while Charlene was also putting a combined sum of almost £2million into the holiday villa in Calvi, and her office redecoration.

'It's crazy!' Mr Palmero wrote. 'I have no control over the Princess's spending'.