Duchess Catherine has developed new ambitions since becoming a mum.
The Duchess - who is set to celebrate her 40th birthday on January 9 - has Prince George, eight, Princess Charlotte, six, and Prince Louis, three, with her husband Prince William, and a family friend feels that motherhood "has been the making of her".
The insider told The Sun on Sunday newspaper: "All Catherine ever wanted was a house in the countryside, loads of kids, dogs and an AGA. She wasn’t interested in having a big job or becoming famous.
"Family life is incredibly important to her, and motherhood has been the making of her.
"Now that she feels she’s achieved that, there’s time to turn to her public role and what she wants to achieve there."
The Duchess spent Christmas with her husband and their children at Anmer Hall in Norfolk.
The royal duo - who tied the knot in 2011 - decided to remain at home over the festive period after Queen Elizabeth opted to stay at Windsor Castle amid rising COVID-19 rates in the UK.
They said in a tweet on Christmas Day: "This Christmas will be different to what so many of us had planned. From those who are alone or having to isolate away from loved ones, to the incredible people supporting our NHS and caring for those most in need – we are thinking of you. W & C (sic)"
Catherine is now planning a small 40th birthday celebration.
The Duchess has decided not to have a big party because of the pandemic.
A source said: "There are likely to be low-key celebrations for the Duchess. She didn’t want anything flashy anyway – that’s not exactly her thing – but particularly given the current climate anything is likely to be scaled down."