LONDON -- Camilla, the Duchess of Cornwall, will celebrate her 75th birthday Sunday, marking the occasion with a small family dinner at Prince Charles鈥 Highgrove estate in southwest England.

The big occasion follows British broadcaster ITV鈥檚 release of a documentary about the duchess鈥檚 stint as guest editor of Country Life, during which she helped produce a special edition celebrating the magazine鈥檚 125th anniversary. In a personal tribute, Camilla selected Charles, her husband, as one of her rural heroes.

鈥淚t鈥檚 not easy to write about your husband,鈥欌 she said in the film. 鈥淚 bit through several pencils.鈥

The milestone birthday comes at a time when the monarchy, and Camilla鈥檚 place in it, are in a generational transition. As the 96-year-old Queen Elizabeth II soldiers on during her twilight years, other members of the royal household are taking on new roles with more responsibilities.

Six months ago, in a statement marking her 70 years on the throne, Queen Elizabeth II expressed her 鈥渟incere wish鈥 that Camilla would be known as 鈥淨ueen Consort鈥 when her son succeeds her. With those words, Elizabeth sought to answer once and for all questions about the status of Camilla, who was initially shunned by fans of the late Princess Diana, Charles鈥 first wife.

The queen鈥檚 statement marked a big moment in Camilla鈥檚 transformation from the 鈥渢hird person鈥 in the marriage of Charles and Diana to consort in waiting. Once blamed for the marriage鈥檚 disintegration, the public has grown to accept her in the years since she married Charles in 2005.

She鈥檚 taken on roles at more than 100 charities, focusing on a wide range of issues including promoting literacy, supporting victims of domestic violence and people who have osteoporosis. Known for having a wicked sense of humour, she has softened Charles鈥 stuffy image and made the heir to the throne seem less remote and more accessible.

鈥淚 do think there has been an amazing transformation in terms of her public persona. She has definitely been groomed. 鈥 She can even look a touch glamorous sometimes,鈥欌 said Pauline Maclaran, author of 鈥淩oyal Fever: The British Monarchy in Consumer Culture.鈥 鈥淪he鈥檚 always very smartly turned out but appropriate for her age. Not so fuddy-duddy as she used to be.鈥欌

Camilla alluded to her approach to royal life earlier this week during a champagne reception and sea bass lunch sponsored by The Oldie magazine, which honoured her birthday.

In a nod to the magazine鈥檚 target audience, the duchess noted that she was born in 1947, the same year that Elizabeth married her late husband, the Duke of Edinburgh. She paid tribute to him, and pledged to emulate his example.

鈥淭he Duke of Edinburgh鈥檚 philosophy was clear 鈥 look up, look out, say less, do more and get on with the job,鈥 she said. 鈥淎nd that鈥檚 just what I intend to do.鈥