Garré was born in the San Telmo barrio of Buenos Aires, and earned a law degree from the Universidad del Salvador when she was 22 years old.

Her father, Raúl Garré, was a Peronist member of the Buenos Aires Province Chamber of Deputies until the 1955 coup against President Juan Perón in 1955.

Informed, as were most lawmakers, that leftist elected officials would be targeted for imprisonment or assassination, she sought refuge with her husband at the Mexican Embassy, where Abal Medina remained for the next six years.

[6] Garré became an ally of Catamarca Province Senator Vicente Saadi and of Peronist Renewal leader Antonio Cafiero upon the return of democracy in elections in 1983.

The government of President Fernando de la Rúa of the Radical Civic Union, which was backed by FrePaSo in an Alliance, was in crisis, however, and Garré resigned in protest over the appointment of conservative economist Ricardo López Murphy as Minister of Economy of Argentina in March 2001.

[9] Garré has also reaped criticism by officials in Buenos Aires Mayor Mauricio Macri's administration for her decision to withdraw Federal Police officers from the city's hospitals, schools, subway stations, and other public places.