January 5, 1762

Elizaveta Petrovna (December 29, 1709 to  January 5, 1762 was the Empress of Russia, born in Moscow. She arranged for the marriage with her nephew to the German princess who would later become Catherine the Great.

Eva Stachniak is a writer, born in Wroclaw, Poland. She moved to Canada in 1981 and has worked for Radio Canada International and Sheridan College, where she taught English and humanities. Her first short story, “Marble Heroes,” was published by The Antigonish Review in 1994, and her debut novel, Necessary Lies, won the Amazon.ca/Books in Canada First Novel Award in 2000. She is also the author of Garden of Venus, which has been translated into seven languages. She lives in Toronto. 

Thus Google Books about the author of a novel about Catherine the Great, titled, The Winter Palace (2012). Here we find the  Empress Elizabeth situated in this scene:

I heard a cat's husky purr.The Empress was running her long, tapered fingers
through its coppery fur......
It is probably unfair of me to criticize an obvious pot-boiler but, this detail of the cat is not historically accurate. I could find no reference to Elizabeth and cats.  Beyond that we have a francophile Russian court of the time, and at Versailles the cat ideal was white Angoras. This pales of course against the larger silliness of the book.