Princess Beatrice turned 37 on Thursday, marking her first birthday since the birth of her youngest daughter, Athena, but the occasion comes as her family faces renewed scrutiny from explosive allegations in an upcoming royal biography.

Beatrice, the eldest daughter of Prince Andrew and Sarah Ferguson, is expected to celebrate privately with her husband, Edoardo Mapelli Mozzi, and their three children - Christopher Woolf, 9, Sienna, 3, and infant Athena, born in January. While the day would normally be cause for celebration, royal biographer Andrew Lownie's forthcoming book Entitled: The Rise and Fall of the House of York has triggered a wave of headlines that royal commentators say may cast a shadow.

The book, excerpts of which were published this week, alleges "hedonistic" lifestyles, controversial friendships, and questionable financial dealings by both the Duke and Duchess of York. It also details claims of affairs during their marriage, extravagant demands by Ferguson after joining the royal family, and tensions within the monarchy. Buckingham Palace declined to comment on the allegations.

Among the most controversial excerpts is an account that Andrew's staff sought to bring attractive women to his events as a trade envoy - a request one diplomat reportedly rebuffed by saying, "I'm not a pimp." Other claims include alleged "rude" remarks about the Princess of Wales and a supposed physical altercation between Prince Andrew and Prince Harry, which a spokesperson for Harry has denied.

Former BBC royal correspondent Jennie Bond told The Mirror that Beatrice is likely "desperately worried about both of her parents" but has learned to "ignore the noise" after years of public scrutiny. "This week's avalanche of lurid reports... will have been an unwelcome 37th birthday gift for Beatrice - but her instinct will be once again to protect her parents," Bond said.

Bond suggested Beatrice's husband will try to keep the day focused on family. "Perhaps a quiet dinner out, or a cosy celebration at home - either way, he knows it's his job to support and comfort his wife on a day that should be full of happiness but will inevitably be tinged with sadness," she said.

The Princess, who is not a working royal, has been active in charitable work. In July, she became the patron of the Chartered College of Teaching, a role previously held by her late grandfather, Prince Philip. "It's a real honour to take up the role... to champion excellence in teaching and to celebrate the impact of this incredible profession," Beatrice said in a statement at the time.

Her last public appearance was at Buckingham Palace for a parade celebrating England's Women's European Championship victory, where Athena was seen in public for the first time.