[Marie] took her son [John] to [Beverly] ([Marie]'s sister) birthday party. [Tracy]'s nephew, [John], brought her lunch at work. [Tracy] was playing in the sandbox with her brother [Pedro].
('Beverly', 'Pedro')
[Marie] took her son [John] to [Beverly] ([Marie]'s sister) birthday party. [Tracy]'s nephew, [John], brought her lunch at work. [Tracy] was playing in the sandbox with her brother [Pedro].
[{('Beverly', 'brother', 'Pedro'): [('Beverly', 'sister', 'Tracy'), ('Tracy', 'brother', 'Pedro')]}, {('Beverly', 'sister', 'Tracy'): [('Beverly', 'sister', 'Marie'), ('Marie', 'sister', 'Tracy')]}, {('Marie', 'sister', 'Tracy'): [('Marie', 'son', 'John'), ('John', 'aunt', 'Tracy')]}]
['sister', 'son', 'aunt', 'brother']