She was born in Silay City, Negros Occidental, Philippines, the daughter of Nicolas Lacson and Amparo Lacson. Her grandfather, General Aniceto Lacson, was a prominent military figure in Negros Occidental during the Philippine Revolution while her uncle, Arsenio Lacson, was the first elected mayor of Manila.
Porteous herself rose to prominence in the 1980s as the central figure in a series of lawsuits launched by her stepdaughter, Gina Rinehart, the daughter of Porteous's late husband, Australian iron ore pioneer, Lang Hancock. Porteous worked as a maid for Hancock, who became her third husband.
Not long after Hancock's death, his widow married her current husband, William Porteous, a Perth real estate agent. Gina Rinehart's lawsuits accused Rose Porteous of marrying Hancock only for his fortune and alleged that her stepmother's actions had contributed to her father's death.
Rose Porteous' brushes with the law include matters relating to insurance fraud and prescription fraud. In October 2005 it was reported that Porteous was being sued for $14 million by Melbourne-based law firm Slater & Gordon for legal fees they claimed she owed for representing her in Rinehart's lawsuits and eventually came to a settlement of $12.5 million.
After a brief stint in the tabloid media, Rose Porteous retreated to a quieter life in Perth and is regarded as a recluse by the locals, although she still occasionally appears on lifestyle programs for television.
In late March 2006, her Perth mansion "Prix d'Amour" was demolished, after being taken off the market. The mansion Rose and Lang Hancock created was an architectural spectacle featuring French doors and windows, parquetry and marble floors and wrought iron. The estate, set on 8100 square meters features the main house, two guest houses, a tennis court and two swimming pools. Then the 'superblock' was subdivided into ten approx. 800 sqm lots (each with maximised views) which were put on the market for around $5 mil. Then in 2008/9 two of these blocks were resold during Perth's 'recession' for a handsome $6,500,000. Each of these blocks have recently been valued at around $7,000,000 each, mostly due to the fact that they are one tenth of the former Prix D'Amour site.
The socialite has been reported as seriously ill and has suffered a recent stroke. She is recovering in the exclusive Perth suburb of Peppermint Grove while she builds her new mansion on two lots of the Prix D'Amour development in Mosman Park, Perth.