She was granted membership in the Samfundet De Nio (The Nine Society) and was awarded the Swedish royal medal Litteris et Artibus in recognition of her writing career.

Her aunt, Sophie Adlersparre (née Leijonhufvud) (1823–1895), was a leading women's rights activist and founder of the Fredrika Bremer Association.

She began working as a teacher at the Åhlin school in 1892, and from 1901, she was employed as a librarian at the Royal Swedish Academy of Letters, History and Antiquities (KVHAA).

With the help her maternal grandfather, Gustaf Adolf Sparre, who was a medievalist, and inspired by historian Ellen Fries, Leijonhufvud continued to research old manuscripts.

She also began contributing literary reviews, short articles, and notes on archival discoveries to academic journals, such as Fornvännen, Fataburen [sv], Karolinska förbundets årsskrift, and Personhistorisk tidskrift.

She was friends with children's writer and illustrator Ottilia Adelborg, historian and suffragette Lydia Wahlström, sculptor Sigrid Blomberg.