'Queen of Versailles' film star Jackie Siegel says sister has died days after mourning death of billionaire husband - what was her cause of death?

The ‘Queen of Versailles’ star, Siegel, 59, made the heartbreaking announcement on her non-profit, the Victoria’s Voice Foundation’s Instagram page on Tuesday (8 April). The socialite wrote: “As I mourn the profound loss of my beloved husband David Siegel, who passed away on April 5 at the age of 89, my world was shattered again yesterday by the unexpected loss of my beautiful sister, Jessica Mallery, 43.

“To a scourge we as a family sadly know too well – accidental drug overdose.” Siegel informed her followers that Mallery “died after using cocaine laced with fentanyl,” adding that her foundation’s work “remains more critical than ever,” and it will continue to raise awareness of substance abuse in her late sister’s honour.

Siegel also shared that her sister’s organs are being donated to help others, and instead of flowers, they ask for donations to be made to the Victoria’s Voice Foundation in Mallery’s honor. Siegel’s billionaire husband — who lived in one of the most expensive homes in the US — died days ago at 89.

The Westgate Resorts founder had been battling cancer, reported the Las Vegas Journal-Review. Siegel honored her late husband following his death.

“I wanted to personally reach out and let you know that my husband, David Alan Siegel, passed away this morning,” she wrote on Instagram on Saturday, April 5, sharing a photo of them cutting their wedding cake. She added: “I was lucky enough to share twenty-five wonderful years with David, and together we raised eight incredible children. His life and legacy live on through them all.”