(LONDON) -- Duchess Kate is starting 2022 with a milestone birthday.
The Duchess of Cambridge turns 40 on Jan. 9, a birthday she is expected to celebrate privately with her family.
Kate, the wife of Prince William and a mother of three, appears to be starting her new decade with a renewed focus on her royal role.
In the nearly 11 years since she wed Prince William at Westminster Abbey, she has become one of the most popular members of Britain's royal family.
And in recent years, Kate has taken on an increasingly high-profile role in the royal family amid family changes.
At age 95, Queen Elizabeth II has scaled back her public engagements, particularly since a brief hospitalization in October. And Prince Harry and Duchess Meghan's decision to step back as senior working royals has left William and Kate, now the only working royals of their generation, to pick up more duties.
The growing public profile has been a "significant transformation" for Kate, who was thrust into the public spotlight when she started dating William while in college, according to ABC News royal contributor Victoria Murphy.
"I think her desire to do a good job, be liked by the public and respected by the family was palpable in the beginning, and she was clearly very nervous when the spotlight was on her over public speaking," said Murphy. "She built up her workload very gradually, taking on only a small number of patronages initially and taking time before making solo appearances and speeches."
"But over the years, Kate has grown hugely in confidence, and is now a driving force behind how she and William work and the causes they take on," she said.
It was Kate, for example, who had the idea to focus on mental health as a cause, according to Murphy, resulting in the very successful Heads Together campaign that launched in 2016 and continues to be a focus of William and Kate's work to this day.
As the Cambridges prepare to one day become king and queen consort, Murphy says the public can expect to see Kate grow even more in her role as she zeroes in on causes close to her heart.
"I’ve always thought that Kate is a team player, cool-headed and a good listener, and that these things have stood her in good stead over the year," said Murphy. "I think she also very much has the ability to compartmentalize, as it has been said the queen does, which is an important quality in handling the pressures of the public role."
Since becoming a mom eight years ago, Kate has focused much of her attention on supporting new parents and young children.
In early 2020, just before the start of the coronavirus pandemic, Kate launched a nationwide survey to explore what people in the U.K. think about raising children, with a focus on kids under age 5.
Then in June of last year, the duchess launched the Royal Foundation Center for Early Childhood, which she said is designed to "raise awareness of why the first five years of life are just so important for our future life outcomes, and what we can do as a society to embrace this golden opportunity to create a happier, more mentally healthy, more nurturing society."
At the same time, Kate and the Royal Foundation, William and Kate's charitable arm, released "Big Change Starts Small," a research report on early childhood development.
Kate has also focused much of her work on making sure the outdoors are included in kids' early development. She helped design a "Back to Nature" garden at the RHS Chelsea Flower Show in 2019, and the next year was named joint president of the U.K. Scout Association, marking the first time a royal woman has held the title of president or joint president of the Scouts.
"I think what has changed in the last few years is that it has become really clear what Kate’s main areas of work are in a way that feels much more focused and immersive," said Murphy. "She has always been interested in the outdoors and in young people, but the fact that she is making those areas cornerstones of her work have become a lot more obvious."
Murphy said Kate's commitment to the cause of early childhood education is particularly striking, noting, "It’s a challenging and very broad area but she has shown a real and serious commitment to it over a long period of time that I think has earned her a lot of respect from people who work in this field."
During the pandemic, Kate offered support for parents and students and teachers, and spoke about the experience of quarantining with and leading virtual learning for her own children, Prince George, 8, Princess Charlotte, 6, and Prince Louis, 3.
The glimpse Kate provided into her and William's home life is just one example of how the duchess' growing confidence has allowed her to be more at ease, according to Murphy.
Kate and William launched a YouTube channel last year, where they share more behind-the-scenes content. And in 2020, Kate gave a rare interview to a motherhood-focused podcast, where she opened up about experiencing mom guilt.
"The [podcast] was a brave move because it could have backfired if people had been critical of the fact she has access to a lot more help than most," said Murphy. "But it ended up being one of the best things she could have done because it really made it clear how hands-on a mother she is and the relatable way she is raising her three children."
Kate has also been more public in recent years about her own passions, whether that is participating in sports, like the tennis game that Kate, an avid fan, played with U.S. Open winner Emma Raducanu last year, or photography.
Kate, a college art major who is often the photographer behind family photos shared with the public, last year launched a photography project, "Hold Still," to capture life during the coronavirus pandemic.
The photographs were compiled in a book in collaboration with the National Portrait Gallery, of which Kate is a patron.
More recently, in December, Kate hosted her first Christmas carol concert at Westminster Abbey, honoring people and organizations who supported their communities during the pandemic.
During the concert, Kate delivered a surprise performance, showing off one of her unknown passions, piano playing, when she accompanied singer Tom Walker.
"These things show a willingness to put herself out there and to let us see more of who she is and what she enjoys," said Murphy.
And while Kate seems to be most in her element when outdoors or with kids, she is also happy to embrace the "glamorous side of royal life," according to Murphy.
She stunned in a gold evening gown at the world premiere of the latest James Bond movie in September, and won praise the next month for wearing a recycled Alexander McQueen gown at the inaugural Earthshot Prize Awards.
"Over the years there has been much excitement when she has worn tiaras from the queen’s collection," said Murphy. "And even a decade into her public role, she still easily commands all the front pages whenever she makes a red carpet appearance."