After graduating from high school in 1988, Andreae studied political science and economics at the University of Freiburg. In 1998 she worked as press secretary and campaign manager to Wilfried Telkämper, then a Member of the European Parliament.
From 1999 to 2002 Andreae was a member of the city council in Freiburg im Breisgau.
In 2002, Andreae was first elected into the German Bundestag. Between 2005 and 2007, she served as the Green parliamentary groups’ coordinator in the Finance Committee. From March 2007 to March 2012 she was the groups’ spokesperson for economic affairs and coordinator in the Committee on Economic Affairs and Technology.
After the 2013 federal elections, Andreae — who is considered a centrist in her party — unsuccessfully tried to become the chairwoman of the Green’s parliamentary group. Commentators regarded her loss against Katrin Göring-Eckardt as a sign that Green lawmakers rejected a chance to reach out to Angela Merkel’s CDU as a possible coalition partner.
In late 2013, when the government announced its plan to significantly increase social expenditures for the current generation of pensioners, Andreae called this a "flagrant pillaging of pension funds" and a "socially unjust" burden on lower- and middle-income individuals.
In August 2012, Andreae was one of 124 members of the Bundestag to sign a letter that was sent to the Russian ambassador to Germany, Vladimir Grinin, expressing concern over the trial against the three members of Pussy Riot. “Being held in detention for months and the threat of lengthy punishment are draconian and disproportionate,” the lawmakers said in the letter. “In a secular and pluralist state, peaceful artistic acts -- even if they can be seen as provocative -- must not lead to the accusation of serious criminal acts that lead to lengthy prison terms.”
- European Academy for Women in Politics and Business, Member of the Board of Trustees
- Federal Network Agency, Member of the Advisory Board
- German Industry Initiative for Energy Efficiency (DENEFF), Member of the Parliamentary Advisory Board
- KfW, Member of the Board of Supervisory Directors
- Protestant University for Applied Sciences Freiburg, Member of the Advisory Board
- Robert Bosch United World College, Member of the Board of Trustees
- University of Freiburg, Member of the Advisory Board
- Quentin Peel (October 8, 2013), Germany Greens set to test waters for possible CDU coalition Financial Times.
- Germany’s Greens: Torn but tempted The Economist, October 10, 2013.
- Alan Crawford and Stefan Nicola (October 10, 2013), German Greens Poised to Rebuff Merkel’s Coalition Overtures Businessweek.
- Markus Dettmer, Kristiana Ludwig, Michael Sauga and Cornelia Schmergal (November 13, 2013), Punishing the Young: German Pension Reforms a Gift for the Elderly Der Spiegel.
- Gernot Heller and Alexandra Hudson (March 18, 2014), Senior German politicians question RWE unit sale to Russian tycoon Reuters.
- Henry Meyer (August 8, 2012), Madonna Urges Freedom for Anti-Putin Punk Girls at Concert Bloomberg News.
- Appell aus dem Bundestag: Deutsche Abgeordnete fordern Milde für Pussy Riot Spiegel Online, August 7, 2012.