18-year-old Victoria Siegel was found in a unconscious when authorities arrived the Seagull Island mansion.
She was pronounced dead after she was sent to a nearby hospital.
she was suspected to have died of drug overdose at the luxury mansion in Florida.
Victoria is the daughter of David and Jackie Siegel. 80-year-old David Siegel is the billionaire founder of Westgate Resorts.
"He and his wife Victoria gained fame and notoriety after the 2012 release of the documentary Queen Of Versailles which followed their attempts to build the self-proclaimed 'largest home in America'.
"They started the project in 2004 but it was stalled after David's business was hit by the failing economy, construction is back on and the sprawls 90,000ft and is expected to be complete by 2016."
Victoria Siegel is the second eldest of the couple's eight children.
See more pictures of the Siegel family and Victoria in the gallery below.