Maria Margaretta Cammann was the daughter of Philip Jacob Oswold of Swabia, Germany. She married Charles Louis Cammann of Loxdedt, Hanover, and was left a widow at the age of thirty years.
She brought up at least eight children on her own. She was known in the Whistler family as 'Grandma C.'
Brooklyn City Directory, New York, 1861, p. 59.