Which preposition to use with charwoman

at Occurrences 1%

It appears that in a recent pilgrimage to Selborne he met the only surviving great-granddaughter of Sarah Timmins (charwoman at Chawton in the years 1810 to 1815), and purchased from her a pair of bedroom slippers, a pink flannel dressing-gown and a boa which had belonged to the great novelist.

by Occurrences 1%

" This stout woman was a certain Madame Joseph, a widow of forty and a charwoman by calling, whom Benard, the husband, had at first engaged to come two hours every morning to attend to the housework, his wife not having strength enough to put on a child's shoes or to set a pot on the fire.

of Occurrences 1%

Dor'othy, charwoman of Old Trapbois the miser and his daughter Martha.

Which preposition to use with  charwoman