Cleaner Leonora Da Costa cared for her elderly boss for so many years he left his house to her in his will.
But just 16 days before Harold Tickner died in June 2015, he changed his mind and wrote up two new documents that disinherited her.
That decision sparked a four-year legal battle over the 91-year-old's estate — but now, Da Costa has finally had a significant triumph after a High Court judge in the UK ruled Tickner had not been of sound mind when the new will was drawn up.
It means Da Costa, 50, will inherit the money remaining in her employer's estate, believed to be around NZ$28,000 (£15,000).
And it also helps to pave the way for her to also claim his NZ$960,000 (£500,000) house in Harrow, London, originally bequeathed to her.
According to Metro, Da Costa first met Tickner when her husband Eduardo was hired to tend to his and his wife Ursula's garden 25 years ago.
Da Costa was then employed to clean the couple's home for three hours per week in 2008 after Mrs Tickner developed Alzheimer's.
But as her condition deteriorated and her husband aged, Da Costa began helping out more and more, eventually working at the home full-time after Mrs Tickner died in 2012.
The Tickners had a daughter, Karen, but the 67-year-old lives overseas, and over the years, Da Costa told the judge she and her boss had developed a "father and daughter" relationship.
In Christmas 2013, Tickner allegedly clashed with his nephew, former barrister Dennis Germain.
Following that disagreement, he decided to leave almost his entire fortune to his cleaner, including his home.
That decision was outlined in a will he wrote in early 2014.
But just weeks before his death from colon cancer in 2015, he apparently had a change of heart, allocating his remaining cash to his daughter in a new will, which he made from his bedside in a nursing home after being transferred there as his health worsened.
He also wrote a separate letter stating Germain was to inherit his house.
But last week, High Court Judge William Henderson overturned the second will, finding Tickner didn't have the mental capacity at the time for it to be ruled valid.
"It seems to me that, on the expert evidence, I would have to conclude that Mr Tickner was incapable of making a will on June 13, 2015," MailOnline reported the judge as saying.
Da Costa told MailOnline her boss would have been upset to learn of the stoush over his will.
"All I wanted was to honour Mr Tickner's wishes," she said.
"He was very independent-minded and would have been furious to see all this. I did what anyone with a conscience would."
The judge's decision regarding the will also clears the way for Da Costa to challenge Tickner's letter promising his house to his nephew, which he wrote on the same day as the second will.
Germain said he did not plan to appeal the judge's decision regarding the will, although it is not known whether he will continue to fight for the home.
Da Costa also claimed she believed she was being kept from seeing her former boss as his health worsened — a claim denied by Mr Germain.
"I find Mrs Da Costa's allegations deeply upsetting, and for the most part, they are totally untrue," he said, according to The Sun.
"It is true that my uncle was very ill when he changed his will. He was, in fact, dying from colon cancer, although neither his daughter nor I were aware of that at the time.
"Far from being 'kept away from the hospital', Mrs Da Costa gave evidence that she visited my uncle every day for the three weeks he was at Northwick Park Hospital but only visited him occasionally after he was transferred to Central Middlesex Hospital because she felt 'nervous' about driving there."