She was born in Buenos Aires in 1937. At 16 she entered the Universidad de Buenos Aires to study literature. In 1957, while working at the National Library, she met the Library's director, Jorge Luis Borges. He introduced her to his fellow writers from Sur magazine. The same year her boyfriend, critic José Luis Ríos Patrón, committed suicide by gunshot in front of her because she refused to marry him.

At the beginning of the sixties, she dated Jorge Luis Borges, and in February 1964 they announced their marriage, although a couple of months later they finally split up. They remained friends and wrote a couple of books together. Vázquez wrote a biography on Borges, ten years after his death, called Borges: Esplendor y derrota (Borges: Splendor and Defeat).

She married writer Horacio Armani in 1964.