Brett was born at No. 1, Tilney Street, Park Lane, Central London, the second daughter of Reginald Baliol Brett, the 2nd Viscount Esher, KCB. Her mother Eleanor was the third daughter of the Belgian politician and revolutionary Sylvain Van de Weyer and his wife Elizabeth, who was the only child of the great financier Joshua Bates of Barings Bank. Sylvia grew up at the family home, Orchard Lea, at Cranbourne in Winkfield parish in Berkshire. Her paternal grandmother Eugenie Meyer was French, born in Lyons. Sylvia Brett grew up in a troubled household. She was ignored by her courtier father, who was far more interested in stalking adolescent boys than being a parent. Sylvia and her sister Dot had to suffer starvation of affection, and she decided to "electrify the world" when she grows up.
Ranee of Sarawak
Brett married His Highness Rajah Vyner of Sarawak at St Peter's Church, Cranbourne, Berkshire, just before her 26th birthday on 21 February 1911. They first met in 1909 when she joined an all-female choral orchestra, established by Vyner's mother. She first visited Sarawak in 1912, where her husband ruled a jungle kingdom on the northern side of Borneo with a population of 500,000, an ethnic mix of Chinese, Malays, and the headhunting Dayak. Brett was invested with the titles of Ranee of Sarawak on 24 May 1917 and Grand Master of The Most IllustriousOrder of the Star of Sarawak on 1 August 1941. Rajah Vyner died in 1963. Brett was distraught that her eldest daughter, Leonora, under Islamic law, could not take the throne; as a result she hatched various plots to blacken the name of the heir apparent, Anthony, the Rajah Muda. She was known for having Machiavellian machinations, which agitated the British Colonial Office. Brett always had designs on her husband's succession because her daughters, as women, were not able to become a ruler of Sarawak. "Her own brother described her as a “female Iago” because she was the family nuisance and great schemer." Richard Halliburton, the celebrated adventurer, met her as he circumnavigated the globe in 1932 with his pilot, Moye Stephens. She became the first woman in Sarawak to fly when the pair gave her a flight in their biplane, the Flying Carpet. Halliburton narrates an account of the visit in his book of the same name. Sylvia Brett enjoyed dressing up in sarongs and exotic jewelry and decorated her London home with spears, totem poles. Brett was the author of eleven books, including "Sylvia of Sarawak" and "Queen of the Head-Hunters". Fort Sylvia in Kapit is named in her honour. She also contributed short stories to publications such as John O'London's Weekly, for example "The Debt Collector", in the Summer Reading Number June 29, 1929.
Dayang Elizabeth, a RADA educated singer and actress, wife of firstly Harry Roy, secondly, Richard Vidmer until her death.
Dayang Nancy Valerie, an actress, known for The Charge of the Light Brigade, wife of firstly, Robert Gregory, an American wrestler; secondly, José Pepi Cabarro – a Spanish businessman; thirdly, Andrew Aitken Macnair ; and fourthly, Memery Whyatt. She died in Florida.