Born to a family of petty Lithuanian nobles, Vaineikienė married physician and activist Liudas Vaineikis.
After the Soviet occupation of Lithuania in June 1940, she became mayor of Palanga, was elected to the People's Seimas, and became a member of the Supreme Court of the Lithuanian SSR.
Vaineikienė was born on 31 March 1884 in Šlaveitai [lt] in the present-day Kretinga District Municipality in a family of petty Lithuanian nobles.
[2] The family spoke Polish, but she learned the Samogitian dialect and secretly taught village's children to read and write in Lithuanian.
[1] She studied foreign languages (German, French)[2] as well as art, literature, music at a girls' boarding school in Łomża.
[1] During World War I, together with her husband, she retreated to Russian and lived in Central Asia (Kyrgyzstan, Emirate of Bukhara, Turkestan Autonomy).
She contributed articles to the magazine Kultūra [lt] and supplied Samogitian words to the Academic Dictionary of Lithuanian.
[1] In 1940, during the German occupation, she published a short article claiming that she was selected for the People's Seimas without her consent and that she knew nothing about its agenda.
[7] The works depict everyday life and customs of a Lithuanian village and are examples of literary realism.
The three-volume Iš praeities kovų (From Past Struggles; 1935–1936) talks book smuggling in the Russian Empire, prison, and internal exile in Siberia.
[1] Vaineikienė wrote Pabėgėlės užrašai (Notes of a Refugee), a memoir about her life in Central Asia and the Russian Civil War.