Sofija was born into a family of the landless gentry. Her parents hardly made ends meet. In 1893, when the girl was 7 years old, her parents moved to Kuliai to live with her mother’s brother, the priest Vincentas Jarulaitis. Sofija’s father farmed in the parsonage, helped with the construction of the new church, and the energetic Elžbieta Kymantienė took over the position of the hostess. With the help of her uncle, Sofija started her education. She was a good, receptive girl – was quick to pick up the Samogitian dialect. Initially, she studied general subjects and music privately, later attended Palanga Primary School for Girls. At the age of 12, she met the young priest Juozas Tumas-Vaižgantas, who had been recently assigned to Kuliai. He became Sofija’s first Lithuanian language teacher. With the funding from her uncle, S. Kymantaitė continued her studies at St. Catherine Gymnasium in St. Petersburg, and in 1904 graduated from Riga Realgymnasium. In 1904–1907, she studied at the Baraniecki Advanced Courses for Women in Kraków and medicine at the University of Kraków. Later she delved into philosophy and literature.
M. K. Čiurlionis also visited Kuliai.