[Constance] went out to dinner with her sister [Martha], and [Martha]'s daughter [Ann].
('Constance', 'Ann')
[Constance] went out to dinner with her sister [Martha], and [Martha]'s daughter [Ann].
[{('Constance', 'niece', 'Ann'): [('Constance', 'sister', 'Martha'), ('Martha', 'daughter', 'Ann')]}]