Soon after Mowbray's death, Mary Ann moved to Seaham Harbour, County Durham, where she struck up a relationship with Joseph Nattrass. During this time, her 3½-year-old daughter, (the second) Margaret Jane, died of typhus fever, leaving her with one child of up to nine she had borne. She returned to Sunderland and took up employment at the Sunderland Infirmary, House of Recovery for the Cure of Contagious Fever, Dispensary and Humane Society. She sent her surviving child, Isabella, to live with her mother.
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Second Relationship in 1871
Soon after, Mary Ann learnt that her former lover, Joseph Nattrass, was living 30 miles away in the County Durham village of West Auckland, and no longer married. She rekindled the romance and persuaded her new family to move near him. Frederick died in December of that year, from "gastric fever." Insurance had been effected on his life and those of his sons.