But who is that child? Could it be Helen "Nellie" Porter Mitchell's adoring granddaughter, Pamela, Lady Vestey – the woman whose wish before her death in 2011 was that the previously private 30-hectares Coombe Estate, the erstwhile home of her grandmother located in the Victorian village of Coldstream, be opened to the public?

On a later tour of the gardens at Coombe, Daniel Johnson, manager of the Melba Estate, confirms my hunch. The girl in the newsreel is indeed Lady Vestey, the daughter of George Armstrong, Melba's only child. Lady Vestey moved back to Coombe following decades living in England after having married Lord Willam Vestey, who died in World War Two. Pamela was devoted to her grandmother as she was too her, even though their time together was brief – Dame Nellie died when Pamela was 12 years old.

An Englishman, Johnson worked for Lady Vestey for eight years prior to her death. He has been instrumental in the estate's stunning transition from a private to public domain. Melba's great-grandsons and Pamela's sons, Lord Samuel Vestey and the Honourable Mark Vestey, have spent millions converting the estate's ramshackle outbuildings, set around a quadrangle, into a cafe-restaurant, gallery and cellar door, selling vintages from the Vestey's nearby Coombe Farm winery, with the gardens the centrepiece attraction.

"The opportunity to make accessible to the public an iconic, private family home with enormous provenance is, we believe, of great cultural value to the local community and all visitors," Johnson says. "It's a celebration of Melba's style, elegance and sense of fun."

I've come to Coombe, which remains one of the largest and oldest family estates in Yarra Valley, an hour or so from Melbourne, in time for an afternoon tour conducted by Johnson of the estate's three-hectare gardens. The gardens are dominated by the estate's homestead, part of the verandah of which feature a pair of high-backed cane chairs which Dame Nellie bought in Honolulu. Descendants of Melba still come to stay at the house, making it ostensibly off-limits to the public.

Perhaps not unlike most Australians of my generation, I've come to Coombe Estate knowing a little about Dame Melba without knowing much. I learn that her repertoire was remarkably small, having sung as a few as 25 operatic roles, one of the most famous being Rossini's The Barber of Seville and discover later that she was the first Australian to appear on the cover of Time magazine (and what an unflattering image of her the editors chose).

Although Melba's memory has faded from the national consciousness, she did make yet another comeback of sorts in recent when she was misguidedly portrayed by Dame Kiri Te Kanawa, a New Zealander, no less, in an episode of Downton Abbey.

Such was the extent of Dame Nellie's celebrity during the peak of her career that it's claimed that for a time she was the most famous woman in the world, though part of her life did span that of Queen Victoria, another woman of some international renown.

In some countries, a place like Coombe, dominated by a grand cypress hedge which rings the property that dates to the 19th century when it was founded by David Mitchell, Melba's father, would have long ago been declared a national monument. Its preservation is a tribute to Lady Vestey with the public opening of Melba Estate a year or so ago rekindling some interest in her grandmother's illustrious and at times scandalous life.

Johnson believes that while Australians enjoy varying levels of knowledge regarding Melba's achievements, most are unaware, like me, of the importance of Coombe as the diva's Australian home.

"She [Melba] put Australia on the map and was the first performer to use her celebrity to raise awareness of social and political issues she supported – something that celebrities do today. She deserves, quite correctly, to be heralded as one of the most important Australians to have ever lived."

The estate itself is as imposing as Dame Nellie herself in her heyday, the gardens – which feature a French-style rose garden, an English herbaceous border and an Italianate garden and pool, thought to be the first built-in pool in Victoria – an eccentric expression her prolific travels.

Exotic species of the day, such as wisteria sinensis tumble over pergolas and trellis, framed by W.R. Guilfoyle's major plantings – himself the curator of Melbourne's Botanic Gardens no less – amid what Johnson describes as "a private garden full of joy" which is true to the original layout of 1911. On the tour of the garden we pass a modest bird-bath in which Melba's granddaughter was christened as well as a pair of sculptured bronze stags, bought in Rome, that sit atop concrete pillars obscured by an ornamental fig.

Johnson points out a photograph of Lady Vestey, aged 10, in Coombe's gallery feeding the stags with grass before they were erected. Melba commissioned Guilfoyle to design her own at Coombe and he set about planting "rare plants and beautiful old world trees" dominated by a magnificent now nearly 200-year-old English oak.

But the gardens aren't the only attraction at Coombe. Melba, who was born in 1861and died in 1931, was a patron of the arts, the opening of Coombe to the public allowing part of her private art collection to be displayed to the public. The careers of Arthur Streeton, and particularly Hans Heysen, says Johnson, are inexorably linked to Melba's support and patronage.

William Dargie, another renowned Australian artist, once called on Melba unannounced when passing Coombe, explaining that he'd done so "because she was [known to be] kind to artists and might even give us afternoon tea". Dargie, and others artists received more than scones with the diva who allowed them to do etchings of the garden, now on display at Coombe's gallery.

Aside from the art which highlights yet another side of Melba, the opening of the estate to the public has also allowed the collection of Melba's possessions to be displayed. These include one of more than a dozen Louis Vuitton travelling trunks and the Dame Grand Cross, the highest civilian order of the British Empire, with Melba having become a dame not in recognition of her singing prowess but for her charitable fund-raising efforts during World War One.

Although the custodians of the estate have been at pains not to create a "Melba World" at Coldstream, there's an elegant restaurant – located in the former motor-house and where Melba once parked her De Dion-Bouton and Rolls-Royce –where Peach Melba is served. The dish is said to have been created by the famed French chef, Auguste Escoffier in her honour.

After an illuminating and nostalgic afternoon at Coombe, a veritable crash (refresher) course in Dame Nellie's life, I leave with an impression that Melba – whose grave is just down the road in Lilydale – may have become notorious for her endless comebacks she at least always came back to her homeland. Dame Joan Sutherland, as was her right, chose to live and be buried in Switzerland, arguing stridently against an Australian republic on her return visits here. But despite the extraordinary travels that characterised her adult life Melba truly called Australia, and Victoria, home, rendering both places better than they may have been without her.

TRIP NOTES

MORE INFORMATION

visitvictoria.com

VISITING THERE

Guided tours of the garden at Coombe: The Melba Estate cost $25 a person and include morning or afternoon tea. The tours, which are the only way to access the gardens, are conducted at 10 am on Mondays and Tuesdays, 10 am and 2 pm on Wednesday, Thursday and Saturday. No tours are held on Sundays or public holidays. Bookings are essential. A souvenir book Melba: a Family Memoir, written by Lady Vestey, can be purchased at the property's gift shop.

GETTING THERE

Coombe, located in the Yarra Valley, is about 50 minutes' drivetime Melbourne and about an hour from Melbourne Airport at Tullamarine. Coombe is at 673-675 Maroondah Highway, Coldstream. Phone (03) 9739 0173, see coombeyarravalley.com.au

STAYING THERE

The Yarra Valley's most prestigious and historic hotel 19th century Chateau Yering is just down the road from Coombe. Rooms at the five-star hotel cost from $395 including breakfast. 42 Melba Highway, Yering, Phone (03) 9237 3333, see chateauyering.com.au

The writer was a guest of Tourism Victoria, Chateau Yering and Coombe: The Melba Estate.