Reaching 30 is a big deal for anyone, but for Catherine, Duchess of Cambridge, it’s a particularly significant birthday – her first as a fully fledged member of the royal family.

From her humble beginnings as the daughter of two former flight attendants, “commoner Kate”, and later “Waity Katie”, has become easily the most enchanting and talked-about member of The Firm since the late Diana, Princess of Wales.

While many had predicted Kate’s 30th birthday celebrations would coincide with a baby announcement, it seems the only declaration we can expect are which charities she’ll be taking on.

Starting a family is apparently on the backburner until later this year because of Prince William and his wife’s commitments during the Queen’s Diamond Jubilee and their role as ambassadors at the London Olympic Games.

Those who know the duchess well say Kate is happier than she has ever been – after all, she has her prince and is deeply in love. However, this week’s milestone may be tinged with disappointment, because Kate had always wanted a baby by this age.

“At school, Catherine was never one of those girls planning a career,” a friend reveals, speaking exclusively to Woman’s Day. “What she wanted was a family, and she always said she wanted a baby by the age of 30. It was something her mother, Carole, also believed was very important. But Kate has accepted things don’t always go to plan and she has too much on her plate for a baby at the moment.”

Read more about Kate Middleton's 30th birthday celebrations and her plans for the coming months in this week's Woman's Day on sale January 9, 2012.