[Heidi] and her sister [Linda] both wanted to play with the same doll. [Heidi]'s mother, [Nancy], told them to share.
('Linda', 'Nancy')
[Heidi] and her sister [Linda] both wanted to play with the same doll. [Heidi]'s mother, [Nancy], told them to share.
[{('Linda', 'mother', 'Nancy'): [('Linda', 'sister', 'Heidi'), ('Heidi', 'mother', 'Nancy')]}]
['sister', 'mother']