About Svetlana Alliluyeva
Svetlana Iosifovna Alliluyeva, later known as Lana Peters, was the youngest child and only daughter of the Soviet leader Joseph Stalin and his second wife, Nadezhda Alliluyeva. In 1967 she became an international sensation when she defected to the United States and, in 1978, became a naturalized American citizen. From 1984 to 1986 she briefly returned to the Soviet Union and had her Soviet citizenship reinstated. She was Stalin's last surviving child. Alliluyeva and Bychokova became quite close, and remained friends for 30 years, until Bychokova died in 1956.
Biography source: Wikipedia. The profile adds birthday-specific historical context from the Celebs Birthday Today editorial database.