[1][2][3] She first sought out a career in journalism in the early 1980s, studying communications and later working as a press consultant for the Universidad Católica "Nuestra Señora de la Asunción".
[1][4][5] When dictator Alfredo Stroessner was overthrown in 1989, Rehnfeldt began working at the independent newspaper ABC Color's weekly magazine Dominical.
[5][6] Decades later, she continues to work as an investigative reporter and editor at ABC Digital–ABC Color, where she is considered one of the publication's most prominent journalists.
[1][5][8] She served as the founding president of the Forum for Paraguayan Journalists (FOPEP), and she teaches journalism at the Universidad Americana in Asunción.
[5][12][13] In 2003, unknown attackers attempted to kidnap her daughter as she returned from school, after Rehnfeldt published investigations into the Paraguayan Catholic Church's handling of sexual abuse.