In 2002, the wife of one of the founding directors of food and beverage company Yeo Hiap Seng made a will, leaving one house each to her elder son's two children.
Over the years, Madam Ng Lay Hua made more wills. By the last one in 2012, she had cut the two grandchildren out completely and, instead, left the two houses to her younger son Henry, whom she also appointed as the sole executor.
Despite a challenge to the validity of the later will by elder son Charles and his two children, the High Court upheld it and found that Madam Ng had the necessary mental capacity to make her last will.
In a 79-page written judgment released on Wednesday, Senior Judge Andrew Ang concluded that Madam Ng's decision to disinherit the two grandchildren was not made on the spur of the moment.
Madam Ng, a Christian, had told family members that she was not leaving her grandson any inheritance as she was disappointed he had married a non-Christian and did not attend church regularly.
While the matriarch did not give a specific reason for excluding her grandaughter from her will, the judge said it was clear that Madam Ng was leaving it to Charles to look after his daughter.
Madam Ng had depression in the last years of her life, but her mental illness was not serious enough to affect her decision to exclude the two grandchildren from her will in 2012, said the judge.
"I find it difficult to accept that just because Madam Ng suffered severe depression, her testamentary disposition had to be set aside."
He noted that Madam Ng did not have dementia and even after being diagnosed with depression in 2006, continued with her normal activities, such as reading newspapers, following TV drama serials, monitoring share prices and attending church meetings.
Madam Ng, whose husband Yeo Chee Kiat is a grandson of Yeo Hiap Seng founder Yeo Keng Lian, had two sons and two daughters. Her husband died in 1985.
Her estate included a detached house in Sian Tuan Avenue, a semi-detached house in Watten Terrace, a detached house in Hua Guan Avenue and a portfolio of stocks and shares.
In 2002, she willed the Sian Tuan house to Charles' son, the Watten Terrace house to Charles' daughter, and the Hua Guan Avenue house to Henry and the daughter of her elder daughter Wee Tsan.
By 2012, the Sian Tuan Avenue and Watten Terrace properties were willed to Henry instead, making him the main beneficiary. Henry is married with no children.
The judge said Madam Ng's decision to leave the bulk of her estate to Henry is "consistent with the high likelihood that he was her favourite son".
The judge noted that Henry cared for Madam Ng in her old age, spoke to her in a quiet and gentle manner, managed her affairs, chauffeured her around, attended church services with her and took her out for meals.
He also noted that Madam Ng had instructed her lawyer to change the wills; this was not a case where a will was prepared on instructions by someone who stood to benefit.
The evidence is in favour of Henry's assertion that Madam Ng knew and approved the contents of the wills, he said.
Commenting on the decision, Senior Counsel Deborah Barker, who represented Henry, said: "Depression does not necessarily vitiate a testator's capacity to make a will. Our client is very happy that the court found there were no suspicious circumstances and upheld Madam Ng's last will."