Career
On 21 December 1904 she was married to Paul Ehrenfest (1880–1933) an Austrian physicist. Afanasyeva was born in Kiev, Ukraine, then part of the Russian Empire. After her father died she was brought up by an uncle in Street St. Petersburg, Russia, where she attended a women"s pedagogical school and a Women"s College.
In 1902 she transferred to Göttingen, where she met Ehrenfest.
The couple got married in 1904, and in 1907 they returned to Street St. Petersburg. In 1912 they moved to Leiden, where Paul Ehrenfest was appointed to succeed H.A. Lorentz as professor at the University of Leiden.
She published many papers on various topics such as randomness and entropy, and teaching geometry to children.