It looks like Mary Ann married James KNIGHT - Ancestry has is an entry for Mary Ann KNIGHT, widow, aged 61, laundress, born St Columb Minor, in the 1901 census.
Ecclesiastical parish: Mawgan in Pydar
County/Island: Cornwall
Country: England
Registration district: St Columb
Sub-registration district: St Columb
ED, institution, or vessel: 1
Neighbors: View others on page
Piece: 2206
Folio: 7
Page Number: 6
Household schedule number: 37