Clara Schumann
Her teacher Clara Schumann was Brahms's closest personal and musical friend, but expressed reservations privately to Brahms about Eibenschütz's playing, writing to Brahms on 1 February 1894 that "she goes too quickly over everything." (The translation is by Jerrold Northrup Moore in his booklet notes to the Pearl CD, "Pupils of Clara Schumann" - Pearl CDS 99049 - which includes recordings of Eibenschütz.)