From January 2010 to November 2017, Kälin sat in the Grand Council of Aargau, where she served as the vice-chairwoman of three committees: the Committee for Responsibility Planning and Finance (2010–2013), the Naturalization Committee (2013–2015) and the Committee for Environment, Building, Transport, Energy and Land Use Planning (2013–2015); besides, she became a member of the Business Examination Committee in 2017.