Kate Middleton has had a massive transformation in recent months, and has come into her own as she approaches her 40th birthday.

According to a report in People magazine, the Duchess of Cambridge is starting a new chapter in her royal and personal life as she is approaching her milestone birthday on January 9 next year. A royal insider said that the royal is "flourishing."

She has also fast-tracked her preparation for the role of future queen consort alongside her husband Prince William. She has started taking on more royal duties since Prince Harry and Meghan Markle stepped back as senior working royals in March last year. The absence of Queen Elizabeth from royal duties due to her recent health issues has also added to Kate's workload.

Most recently, the Duchess of Cambridge hosted her first-ever Christmas carol concert at Westminster Abbey to honour the individuals and organisations across the U.K. who have supported their communities throughout the COVID-19 pandemic. Kate wrote about the concert, "Through our separation from others, we have been reminded just how powerful human connection is to us all. Just how much we need one another. And how loving and feeling a sense of belonging to one another can provide comfort in tough times. The importance of simply being together."

Joan Black, who attended the concert, told the outlet that what Kate wrote was "beautiful." He said, "...to bring everyone together like this is lovely. I felt she was really confident. We are doing well if that's our future Queen."

Meanwhile, the Duchess has moved into a new phase in her family life. Her youngest son Prince Louis, three-year-old, is off to nursery school, and all three of their children are out of the toddler years. However, she continues to be actively involved in their lives despite the helpful hand of nanny Maria Turrion Borrallo.

A source previously told Us Weekly that Kate has even left the Queen impressed with her transformation. The insider said, "Over time, Kate has proved to Elizabeth that she can be trusted and they've developed a great relationship. Elizabeth feels confident that Kate will make a great queen."

Kate Middleton
Kate Middleton, the Duchess of Cambridge Oli Scarff/POOL/AFP via Getty Images