[6] Grigory was one of the pioneer oil prospectors of the Baku fields and a chief stockholder in the Lena Gold Mining Partnership,[7] as well as a director of the Russian and English Bank Limited of Saint Petersburg.

[10][5] After her mother's death on 27 April 1926, in Nice,[11] Benenson moved permanently to Manhattan,[12][Notes 1] where on 19 March 1931, she married Janusz Ilinski, a Polish nobleman and soldier.

[12] [15] His father's investments in real estate in New York allowed Fira to open, with her partner Vera Heller, Verben, an exclusive dress shop between 5th and 6th Avenues on 57th Street.

[16] When the family fortune took a downturn due to the Great Depression and the aftermath of the Wall Street crash of 1929, Benenson opened a dress shop in New York City, gaining a reputation in the fashion industry.

[2][18] While other designers utilized padded shoulders, Benenson preferred natural lines and silhouettes that balanced a woman's figure.

[2][21] She had become one of the top fashion designers in the United States by 1950,[22] and counted among her clients, Princess Grace of Monaco[23] and Pat Nixon.

[24] Increasingly she designed clothes for women over forty, putting out two collections each year for the ready-to-wear market,[2][18] while still keeping her styles though available in a range of sizes, with the feel of made to order garments.