[1] She hailed from an established family, and her father was Fridolf Almqvist who served as the director general of the National Prisons Board.

[2] Carl Jonas Love Almqvist, an author, was her father's half-brother.

[3] She married Hjalmar Hammarskjöld, and they lived in Vasa Castle.

[6] She was one of the confidants of Lars Olof Jonathan Soderblom, the Lutheran bishop of Uppsala.

[2][7] In October 2011 a book about her entitled Agnes dag: en bild av Agnes Maria Carolina Almquist, gift Hammarskjöld was published by Lisa Segerhed.