But she is upset to now find it has gone missing - its concrete foundation has been smashed and the headstone stolen.
Mrs De Lilla is hoping someone may know where the granite headstone is and let Cromwell police know or somehow return it.
If it does not come back? ''I think I'll have to replace it. It'll drive me crazy otherwise.''
The story surrounding the headstone started in 2005 when Mrs De Lilla was living in South America and started researching her family history.
One of her great-great-grandfather's siblings was George Paul, born in Scotland on November 2, 1820. She found an advertisement placed by someone looking for him, last known ''on the Nevis''.
At first she thought that was a boat, then discovered it was the Nevis River and George Paul was a miner. Further research revealed he was a successful miner, with a November 19, 1864, news article about him and three others making a gold strike near Clyde.
He remained single, continued mining with others and was involved in projects such as the Nevis water race before he died on July 20, 1891, aged 70 years.
He was buried in plot 5, block 8 at the Cromwell Cemetery, in a grave without a headstone.
So Mrs De Lilla had a Dunedin company put a headstone on the grave in 2009. When she returned to New Zealand that year, she came down to Central Otago and photographed it.
After the Christchurch earthquakes, she and her husband shifted to Alexandra about four months ago, and they went to the grave to get another photograph. But they found the headstone had gone missing.
''It's really bizarre. It was quite a big headstone and would be difficult to carry away.''
While the concrete foundation was smashed, there were no granite fragments and she assumed it had been stolen.
Mrs De Lilla had been told other headstones had also gone missing.
Cromwell police Constable Phil Beckwich said finding the headstone could be difficult, but publicity may help locate it.
''It is a cold trail, but we will follow up on inquiries she [Mrs De Lilla] has made and see if we can find anything,'' he said.
He would welcome any information on the whereabouts of the headstone.
