Born in Rehren [de] the daughter of the cellist Friedrich-Jürgen Sellheim, Katharina appeared in public first in 1994, with her father.

A year later she won first prize in the national competition Jugend musiziert in two categories, piano solo and vocal accompaniment.

[1] Sellheim studied at the Musikhochschule Hannover with Karl-Heinz Kämmerling and Markus Becker, and in Paris at the Ecole Normale de Musique Alfred Cortot with Germaine Mounier.

[1] She accompanied at master classes including their concerts of Fischer-Dieskau with lieder by Hugo Wolf on poems by Mörike and Goethe.

[3] She has performed as part of the Klaviertrio Hannover with violinist Lucja Madziar and cellist Johannes Krebs, including concerts at the Beethovenfest in Bonn, the Elbphilharmonie in Hamburg where they played Beethoven's Piano Trio, Op.

Together with the Klaviertrio Hannover and her brother Konstantin Sellheim, viola, she recorded a CD of Beethoven's Piano Quartets, WoO 36 1-3 and Op.