In her career as a singer she appeared at the court opera of St. Petersburg, at the Stadttheater Düsseldorf and at the Krolloper in Berlin.
In 1870 she appeared at the German Theater in Amsterdam [de] and in Wiesbaden as guest singer.
[6] Her performances as Donna Anna in Don Giovanni, as Leonore in Fidelio, in the title role in Euryanthe by Weber and as Frau Fluth in The Merry Wives of Windsor by Otto Nicolai were famous.
[7] After finishing her active stage career she worked as a singing teacher in Berlin.
Miss Mannstein is beautiful, enchantingly beautiful, even outside the stage, she is reminiscent of Heine's poem: The Woman's Body is a poem written by God the Lord.She had one son, Oswald Kohut (1877–1951).