The NASA reference for the Cape archive shown under overview relates to the marriage of Susannah Elizabeth Maria Ferreira, Agatha Catharina's sister, and her marriage to Cornelis Johannes Muller. Both sisters married Cornelis Johannes Mullers each of whose father was also named Cornelis Johannes Muller. They, however, married two entirely different people. Agatha Catharina's Cornelis died in 1844 and did not marry her sister as his second wife.