Today marks the Duchess of Sussex's 40th birthday. She is expected to throw a glamorous and exclusive party at her multi-million dollar mansion in Montecito, California, on Wednesday. The Royal Family Twitter account shared three pictures featuring the Duchess of Sussex and a lovely message dedicated to Meghan as she hit the milestone.

       It read: "Wishing The Duchess of Sussex a very Happy Birthday today!"

       Among the pictures included in the montage is one taken in the summer of 2018 during a joint engagement carried out by the Queen and Meghan; another from Southern Africa during the Sussex's 2019 tour; and the last showing Meghan and Harry during their last ever royal engagement, smiling, in March 2020.

       This birthday will double up as a special event for Meghan given that she recently welcomed her second child, Lilibet, into the world.

       Her birth came with the announcement that Meghan and Harry would be taking several months of maternity and paternity leave.

       This was in line with the policy at their charitable foundation, Archewell, which gives employees 20 weeks of paid leave.

       Yet, it runs in stark contrast to the standard US parental leave agreements - a market of people they are desperately trying to appeal to given where they're based.

       Marlene Koenig, a veteran royal expert, said it would be a blow to their image in the eyes of average Americans who cannot relate to being given such a privileged amount of leave.

       She told Express.co.uk: "We don't have paid paternity leave in the US, it's up to your employer.

       JUST IN: Royal Family LIVE: Prince Charles praised for cryptic photo choice

       "So that to me was like it's great, but the average American can't relate to it.

       "Federal workers now have paid maternity leave - six or 12 weeks - with the family leave act.

       "It's a really nice thing for them to have, but if Harry is going to advocate for people, perhaps he could advocate for the fact that most Americans don't get the paid leave that he's having."

       However, she conceded: "That's something he can't change, though.

       DON'T MISS

       Meghan and Harry Netflix deal torn apart: 'Don't deserve it!' [REPORT]

       Most-feared biographer vows to 'tell truth about Duchess [INSIGHT]

       Kate and William poised for holiday washout [ANALYSIS]

       "But to me, he's not always in tune.

       "That said, they do want to help people, they have been helping, they just gave things to a women's shelter in LA."

       The couple didn't enjoy such a lengthy period of leave after the birth of their first child, Archie.

       Although initial reports suggested Harry would take a two-week paternity leave - the UK standard - when Archie was born, he was on a flight to the Netherlands for the Invictus Games just three days later.

       Meghan was accompanied by her mother, Doria Ragland, during this time.

       The Duchess took around four months maternity leave for Archie.

       Typically, the Royal Family follows the same parental leave as British citizens: six months for maternity and two weeks for paternity

       But Prince William and Kate, Duchess of Cambridge, also failed to follow this standard.

       Kate took one month off after Prince George was born, five months for Princess Charlotte, and six months for Prince Louis.

       William took two weeks for his first two children, and none at all for Louis.

       He was famously pictured dozing off at an event two days after Louis' birth.