She has undertaken important archaeological work in Helsingborg around St Clemens Church indicating the existence of a wooden church there in the early 11th century.
[1][2] Born in Lund, Hallerdt was the daughter of engineer Åke Esbjörnsson (1883–1974) and the gymnast Sigrid Andersén (1891–1985).
[3] In 1949, she married Stig Weidhagen and, in 1968, the writer and curator Björn Hallerdt.
[1] She studied at Lund University, graduating in 1953 and earning a licentiate in 1972.
[1] She bore three daughters, Katarina Weidhagen, Miriam Andersén and Malena Hallerdt.