The couple emigrated to Sweden when Hamburg was taken by Napoleon in 1806, and in 1813, they bought the manor Herrestad.
During the famines in the 1830s when the crops failed, Petersen arranged, in collaboration with the authorities, the Fruntimmersföreningen i Kärda ('Kärda Women's Society'), a society that provided work for poor women within the parish with her estate in the center of the organization.
The principle of the society was economic funds given to the poor upon religious humanitarian grounds in exchange for a workforce.
The society gradually expanded to surrounding parishes: it became famous and received economic support both nationally and internationally.
Petersen had a number of visitors, including revivalists Carl Olof Rosenius, Mathilda Foy, and Amelie von Braun.