[Nicholas]'s sister, [Theresa], bought movie tickets at a discount rate. [Theresa] and her brother [George] were having a wonderful time at Disneyland.
('Nicholas', 'George')
[Nicholas]'s sister, [Theresa], bought movie tickets at a discount rate. [Theresa] and her brother [George] were having a wonderful time at Disneyland.
[{('Nicholas', 'brother', 'George'): [('Nicholas', 'sister', 'Theresa'), ('Theresa', 'brother', 'George')]}]
['sister', 'brother']