[Harold] bought his granddaughter [Cheryl] a skirt. [Heather] and her sister [Rebecca] played golf together. [Heather] won easily. [Annie] went to the store with her sister [Cheryl]. Later that day, [Annie] had tea with her sister [Heather].
('Rebecca', 'Harold')
[Heather] and her sister [Rebecca] played golf together. [Heather] won easily. [Annie] went to the store with her sister [Cheryl]. Later that day, [Annie] had tea with her sister [Heather]. [Harold] bought his granddaughter [Cheryl] a skirt.
[{('Rebecca', 'grandfather', 'Harold'): [('Rebecca', 'sister', 'Heather'), ('Heather', 'grandfather', 'Harold')]}, {('Heather', 'grandfather', 'Harold'): [('Heather', 'sister', 'Cheryl'), ('Cheryl', 'grandfather', 'Harold')]}, {('Heather', 'sister', 'Cheryl'): [('Heather', 'sister', 'Annie'), ('Annie', 'sister', 'Cheryl')]}]
['sister', 'sister', 'sister', 'grandfather']