In the field of university teaching, she has been a professor of administrative law at the Pontificia Universidad Católica del Perú.

From March 2004 to October 2009, she was advisor to the general management and the presidency of the Peruvian Institute of Business Action (IPAE).

On July 23, 2012, she was sworn as Minister of Justice and Human Rights, forming part of the third cabinet of president Ollanta Humala, led by Juan Jiménez Mayor.

Immediately, several Peruvian parliamentarians warned that the Congress of the Republic had given permission only for an international tour of Asia, but not France, for which a “constitutional violation” would have been committed.

[8][9] On October 11, 2013, Rivas appeared before Congress to explain this situation; she justified the arrival of President Humala in Paris, arguing that it was only a "technical stopover", but not a trip; she also maintained that the meeting with the French president was “informal,” thus justifying the fact that Congress had not been asked for permission, without taking into account that State issues were discussed at the bilateral meeting.

On October 20, after four hours of intense deliberation, the Congress went to the vote, which was favorable: 54 votes against censorship, 52 in favor and 4 abstentions[10][11][12] An important event that occurred during her term at the Foreign Ministry was the International Court of Justice verdict on the controversy of maritime delimitation between Chile and Peru, on January 27, 2014, by which Peru recovered 50 thousand km² of sea.