[Nicholas] bought a dress for his daughter [Jennifer]. [Nicholas] bought a book for his son [Milton].
('Milton', 'Jennifer')
[Nicholas] bought a book for his son [Milton]. [Nicholas] bought a dress for his daughter [Jennifer].
[{('Milton', 'sister', 'Jennifer'): [('Milton', 'father', 'Nicholas'), ('Nicholas', 'daughter', 'Jennifer')]}]
['father', 'daughter']