[Jacob] and his sister [Heidi] made a card for [Heidi]'s mother [Nancy].
('Nancy', 'Jacob')
[Jacob] and his sister [Heidi] made a card for [Heidi]'s mother [Nancy].
[{('Nancy', 'son', 'Jacob'): [('Nancy', 'daughter', 'Heidi'), ('Heidi', 'brother', 'Jacob')]}]
['daughter', 'brother']