Grönwall worked as a maid from 1900 to 1934. In 1933, she became a member of the committee founded to examine the working conditions of domestics, and in 1934, she became deputy chairman of the trade union for domestics, Stockholms hembiträdesförening. She was the founder of the Central Comitté of Domestics, Hembiträdesföreningarnas centralkommitté, in 1936. Grönwall was a member of the city council of Stockholm Municipality for the social democrats.