EXCERPT: At Trieste a schoolmistress named Mary Tressa fell in love with a married man with a wife and three children. She contrived to poison his wife and the children, in the hope that she would then be able to marry the man herself.
Without attracting suspicion to herself, Mary Tressa poisoned her own mother, who had remonstrated with her regarding her relations with the married man. Finally she poisoned her lover, who, when he became a widower, refused to marry her. Tressa is also awaiting her trial.
[“Two Female Fiends. Sensational Murder Cases In Austria-Hungary.” Daily Mail (London, England), Oct. 31, 1898, p. 5]
NOTE: The full article discusses two different cases. This is the complete description of the Tressa case.