Esther Ballestrino was born in Paraguay on January 1918. She got a teaching degree, and went on to get a doctorate in biochemestry and pharmacy. She was an organizer of the Women's Movement in Paraguay and was active in local politics. In 1947 she moved to Buenos Aires, where she continued her work helping refugees from Paraguay who were fleeing persecution by the Stroessner regime. In Buenos Aires she married Jesús Carega and had three daughters to whom she dedicated most of her time.

In 1976 two of her sons-in-law (Manuel Carlos Cuevas e Ives Domergue) were disappeared. In 1977 her daughter Ana María was alsto taken. Esther joined the Mothers of Plaza de Mayo y became one of the main organizers. She also worked with Familiares and with the Liga Argentina por los Derechos del Hombre. Her daughter Ana Maria was freed from the concentration camp El Atletico after four months of imprisonment, during which she was savagely tortured even though she was pregnant. Ana Maria and her sisters sought refute in Brazil and later in Sweeden, and though Esther went with them at first she returned to Argentina to continue the struggle to find the disappeared. As she told the other Mothers "my obligation is to be here. I will go on until we find them all."