Princess Kate, upon her entry into the Royal Family, made it clear she had certain expectations, with Prince William conveying her 'terms' to both Queen Elizabeth and Prince Charles back in early 2015, according to sources within the Palace.

The couple's engagement was announced in 2010, with Prince William recounting the romantic proposal during a holiday in Kenya, where he presented Kate with his late mother Princess Diana's ring. In an ITV interview, he explained that using Diana's ring was "my way of keeping [my mother] sort of close to it all".

Their wedding took place on Friday, 29 April 2011 at Westminster Abbey in London, marking Kate's transition into Royal life and the beginning of her duties as a working member of the Royal Family.

However, Kate didn't simply acquiesce to her new role without setting some boundaries. Robert Jobson, in his latest biography titled 'Catherine, the Princess of Wales: The biography', reveals that Kate established key stipulations before fully embracing her Royal duties.

Jobson writes in MailOnline: "Before joining 'the Firm', she wisely established some fundamental rules. She wouldn't be pigeon-holed into carrying out particular duties and insisted on eventually having her full quota of maternity leave, away from the glare of the media and public.", reports the Mirror.

The now Princess of Wales made it clear to senior royals that her priority would be striking a balance between fulfilling Royal duties and nurturing a happy family life, according to Mr Jobson. "This didn't mean that she wouldn't carry out royal duties; far from it," he states.

"But she wanted to offer her patronage only to charities close to her interests and delve into their purpose with in-depth study."

He further reveals that these 'terms' were actually presented by Prince William to Queen Elizabeth and Prince Charles in early 2015, when Kate was expecting Charlotte. On her behalf, he explained that she desired more room to grow into her role and required additional time to adjust to the peculiarities of Royal life.

Since then, Kate has certainly risen to her responsibilities both as a senior Royal and as a devoted full-time mother to her three children. She is recognised for her role as a peacemaker between her husband and Prince Charles, with their relationship having significantly improved due to her gentle interventions.

When asked in her first engagement interview if she was apprehensive about stepping into the shoes of the late Diana, Princess of Wales, Kate admitted "yes," but it's evident since assuming the role that she has made it distinctly her own, leaving her unique mark on her sector of the monarchy.