The duchess Anastasia Nikolaevna died at the age of 17. Here is all you want to know, and more!
Biography - A Short Wiki
Youngest daughter of Tsar Nicholas II, who was assassinated by Russian secret police. She became the center of several conspiracy theories, which postulated that she was still alive and in hiding.
She had three older sisters: Olga, Tatiana and Maria. She also had a younger brother named Alexei.