She is best known for editing and translating European poetry ranging from the Middle Ages into Finnish in a comprehensive anthology entitled Tuhat Laulujen Vuotta in 1957.

She participated in the Art Competitions of the 1948 Summer Olympics in London, and won the gold medal in the Lyric Works, Literature category for "Laurel of Hellas".

[1] Tynni was born in Ingria into an Ingrian Finnish family.

[2] She married fellow poet Martti Haavio, her second husband, in 1960.

After he died in 1973, Tynni and Katariina Eskola compiled his notes and correspondence, which were later released as a series of books.