She is known as a pioneer of the Sunday school, and as the co-founder of the charity organisation Fruntimmersällskapet för fångars förbättring ('Women's Society for the Improvement of Prisoners') in 1854.

[2] She was the daughter of the British consul in Stockholm, George Foy, and his Swedish wife Mathilda Augusta Skoge.

Cultural historian Gustaf Näsström, in his book Det gamla Medevi, retells a love story from the diary that brings to mind Jane Austen writing a novel about events in Bath.

[4] In Stockholm as a young woman, Foy was likely influenced by Methodist minister Joseph Rayner Stephens and by his successor George Scott.

The person with the greatest religious impact on her, however, was Lutheran Pietist revivalist preacher Carl Olof Rosenius.

In 1854, she co-founded the Fruntimmersällskapet för fångars förbättring ('Women's Society for the Improvement of Prisoners') together with Cederschiöld, Fredrika Bremer, Betty Ehrenborg, and Emilia Elmblad.

"[12][13]In 1858, four anonymous pamphlets, 32 pages each in small format 100 x 67 mm, were published by the cantor Per Palmquist (1815–1887), including "Mormor på Herrestad".

[14][15] Foy also tells how Petersen became a purveyor to the court, how she started a working society with help from her native Germany in a time of severe famine, and how King Charles XIV John – because it was written in foreign newspapers without his knowledge that Sweden's distress required foreign aid – sent the governor to investigate the situation; the result of the governor's report was that the king placed an order for 1,500 riksdaler worth of cloth annually for as long as he lived and she continued with her workers' association.