Until the start of World War I, she taught Lithuanian language and literature at teachers' courses established by the Saulė Society in Kaunas.

In her essays on art and literature, influenced by ideas of fin de siècle and Young Poland movements, she criticized realism and supported symbolism.

The family lived with her maternal uncle Catholic priest Vincentas Jarulaitis [lt] who taught her privately and sponsored her education.

[1][2] When her parents' business – a guest house and a small shop in Šiauliai – failed, the family moved back to live with Jarulaitis in Kuliai in 1893.

[4] The same year, Kymantaitė met priest Juozas Tumas-Vaižgantas, an active participant in the Lithuanian National Revival and editor of Tėvynės sargas, who was assigned to Kuliai.

[7] When her uncle Jarulaitis suffered a fire and could no longer support her education,[8] Kymantaitė returned to Lithuania and joined the cultural life of Vilnius in 1907.

Encouraged by Juozas Tumas-Vaižgantas, she took a job at the office of Viltis (Hope) and contributed articles and feuilletons on Lithuanian literature.

[10] Kymantaitė delivered a speech on teaching the history of Lithuania and was elected to a 10-person committee charged with the establishment of the Lithuanian Women's Union.

[10] She also participated in the activities of the Rūta Society; for example, she performed the main female role of Aldona in the historical play Mindaugas by Juliusz Słowacki in May 1908.

[8] Kymantaitė and Čiurlionis met again in November 1907 at an event commemorating Vincas Kudirka during which she delivered a speech and he played a piano.

[8] During their short relationship, the couple worked on a few joint projects – organized the Second Lithuanian Art Exhibition, published a collection of literary criticism Lietuvoje (In Lithuania; 1910), painted a backdrop for the Rūta Society (she painted tulip ornaments in the Lithuanian folk style), and worked on an unfinished opera Jūratė.

[1] To raise funds to support struggling students, activists organized cultural evenings with lectures, music, plays.

[15] During World War I, she evacuated to Voronezh and taught at the Lithuanian teachers' courses and girls' school established by Martynas Yčas.

She collected material for a book on the methodology of teaching Lithuanian language and literature, but it was not finished due to World War II.

In March 1929, she attended a meeting on the situation in Eastern Europe organized by the Women's International League for Peace and Freedom (WILPF) in Vienna.

[17] In 1930, she joined the League's Fifth Committee which dealt with social and humanitarian questions such as human trafficking, prostitution, children's welfare.

The union sought to help young women who moved from villages to larger cities to avoid being exploited or trafficked.

Frequent visitors included Vincas Mykolaitis-Putinas, Balys Sruoga, Salomėja Nėris, Kostas Korsaks [lt].

[7][22] She later published her literary works and critical essays in various anthologies and periodicals, including Naujoji Romuva, Lietuva, Aušrinė.

[23] When her criticism of Sudrumsta ramybė (Disturbed Peace), a 1925 play by Petras Vaičiūnas [lt], was not well received, she stopped publishing her reviews.

Influenced by ideas of fin de siècle and Young Poland movements,[25] she was dissatisfied with realism which was prevalent at the time and supported symbolism that sought deeper and more significant meaning, explored spiritual life and longing.

[9] In her various essays on art and literature, she urged creators not to copy foreign examples but to look within oneself, to explore the national character and spirit embodied in the Lithuanian folklore, and to create more modern works.

[9] These comedies by contrasting idealism with materialism showed the society's flaws and poked fun at greed and desire for profit.

[25][26] Another comedy Didžioji mugė (The Great Fair; 1939) explored families of the new capitalist elite – husbands chasing money and fame and their vain wives launching charitable initiatives and flirting with the Americans.

[26] Her drama Aušros sūnūs (Sons of Aušra; 1922) depicted the lives of book smugglers during the Lithuanian press ban.

[26] It depicts one parish in Samogitia during the Lithuanian press ban and paints a picture of social and cultural life at the time.

[27] The National Revival is also explored in the novel Bundanti žemė (Awakening Earth; 1913–1934) which depicts the lives of two young friends, one from the nobility, the other from the peasantry, and their paths to active cultural work.

[9] In 2017, Valentinas Masalskis [lt] who played Čiurlionis in the 1986 film established an annual art and music festival named Sofija in her honor.