Last year, the sisters suffered the death of their father, Jorge Zorreguieta, who died at 89 years old in August 2017.
Zorreguieta was a psychologist who once worked for an office on social policies at the president's office.
Zorreguieta acted as one of Maxima's bridesmaids at her wedding to Dutch King Willem-Alexander in 2002 and was the godmother to the royal couple's third daughter, Princess Ariane.
Tributes were paid to the "very handsome and talented" Zorreguieta on a video her brother Martin posted of her singing and playing the guitar past year.
The father of Inés and Maxima, Jorge Zorreguieta, served as agriculture minister during Argentina's brutal military dictatorship and died previous year of Hodgkin's lymphoma at 89.
It said Maxima was close to her sister, who was 13 years younger.
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