[Nancy] wants to make a special meal for her daughter [Heidi]'s birthday. [Robert] sent flowers to his mother [Nancy] for Mother's Day.
('Robert', 'Heidi')
[Robert] sent flowers to his mother [Nancy] for Mother's Day. [Nancy] wants to make a special meal for her daughter [Heidi]'s birthday.
[{('Robert', 'sister', 'Heidi'): [('Robert', 'mother', 'Nancy'), ('Nancy', 'daughter', 'Heidi')]}]
['mother', 'daughter']