She created, among others, the roles of Elsa in Wagner's Lohengrin, conducted by Liszt in 1850, and Margiana in Der Barbier von Bagdad by Peter Cornelius in 1858.

[1] Her father Friedrich Wilhelm Agthe [de],[a] a chamber musician, gave her piano lessons at a young age.

[2] She made her official debut as a permanent singer at the Hoftheater in September 1848[3] in the title role of Louis Spohr's Jessonda.

The couple often appeared together on stage, for example in 1852 as Teresa and Fieramosca in the first German production of Benvenuto Cellini by Berlioz, in an arrangement by Liszt.

[1] In 1854, Milde participated in the world premieres of both Heinrich Dorn's Die Nibelungen and Schubert's Alfonso und Estrella.