Schlotthauer was born on 22 August 1963 in Isidro Casanova, a city in La Matanza Partido, in the Greater Buenos Aires conurbation.

Raised Roman Catholic, she became an atheist as a teenager and joined the Socialist Workers' Party toward the end of the last military dictatorship in Argentina (1976–1986).

[1] She was a union delegate in the Sanatorio Antártida hospital, in Buenos Aires, until she was fired during the administration of Carlos Menem.

In 2005, she left for Venezuela to support the National Workers' Union, until she was forced to return to Argentina due to economic limitations.

[1] Schlotthauer ran for a seat in the Buenos Aires Province Chamber of Deputies in 2015 general election for the Workers' Left Front (FIT); although she was not elected, she took office on 14 December 2016 due to the FIT's seat rotation agreement, succeeding the Workers' Party's Guillermo Kane.