Gebel was 27th on the Greens state list in the 2011 Berlin state election and was not elected to the Abgeordnetenhaus. She also ran in the Mitte 2 constituency, winning 15.5% of votes. After the resignation of Felicitas Kubala in January 2013, Gebel replaced her as member of the Abgeordnetenhaus. There, she joined the Urban Development and Environment Committee and the Europe, Federalism, and Media Committee. She also became spokeswoman for environmental policy for the Greens.
