[Richard] took his mother, [Helen], and his sister, [Dorothea], to the store. [Dorothea] and her brother [Glenn] went to the basketball game and had a great time.
('Glenn', 'Helen')
[Dorothea] and her brother [Glenn] went to the basketball game and had a great time. [Richard] took his mother, [Helen], and his sister, [Dorothea], to the store.
[{('Glenn', 'mother', 'Helen'): [('Glenn', 'brother', 'Richard'), ('Richard', 'mother', 'Helen')]}, {('Glenn', 'brother', 'Richard'): [('Glenn', 'sister', 'Dorothea'), ('Dorothea', 'brother', 'Richard')]}]