[Tracy] called her brother, [Pedro], up to see how he was doing after surgery. [Robert] and his wife, [Marie], took [Robert]'s daughter [Michelle] to the park for a nice day in the sun. [Marie] is one of my favorite students. She is the younger sister of [Pedro], who I taught last year,
('Tracy', 'Michelle')
[Tracy] called her brother, [Pedro], up to see how he was doing after surgery. [Marie] is one of my favorite students. She is the younger sister of [Pedro], who I taught last year, [Robert] and his wife, [Marie], took [Robert]'s daughter [Michelle] to the park for a nice day in the sun.
[{('Tracy', 'niece', 'Michelle'): [('Tracy', 'sister', 'Marie'), ('Marie', 'daughter', 'Michelle')]}, {('Marie', 'daughter', 'Michelle'): [('Marie', 'husband', 'Robert'), ('Robert', 'daughter', 'Michelle')]}, {('Tracy', 'sister', 'Marie'): [('Tracy', 'brother', 'Pedro'), ('Pedro', 'sister', 'Marie')]}]
['brother', 'sister', 'husband', 'daughter']