Besides her native language of German, she is also fluent in English, French and Spanish, as well as speaking some Turkish and Arabic.

[6] From 2009 to 2011, Keller also served as member of the European Parliament's High-Level Contact Group for Relations with the Turkish Cypriot Community in the Northern Part of the Island (CYTR).

[8] On 24 November 2018, Keller was elected leading candidate for the second time, together with Bas Eickhout.

[10][11] In September 2022, Keller announced her resignation as co-chair of her party's group and her decision not to run again in the 2024 elections.

[15] In September 2019, European Commission President-elect Ursula von der Leyen created the new position of "Vice President for Protecting our European Way of Life", who will be responsible for upholding the rule-of-law, internal security and migration.

[16] Keller said it was "scary to see a proposal for a portfolio on 'protecting the European way of life' which includes migration and border protection.