Holterhoff performed to acclaim in Berlin in 1910. In 1911 she gave a series of concerts to benefit the Grand Ducal Institute for the Blind. On her return to North America, Holterhoff performed across the United States in 1910s, sometimes billed as "the
Helen Keller of music. After her Chicago debut at the Ziegfeld Theatre in 1917, where a reporter found "the quality of the voice is exceedingly sweet and this – coupled with an engaging gentleness of manner in the singer combines to make her thoroughly charming." Later in 1917, she gave a concert at
Aeolian Hall in New York to benefit "blind soldiers in France". She became interested in helping disabled veterans more directly. After studying medicine and psychology at Columbia University and earning a medical degree in the 1920s, Leila Mosher earned another professional degree from the University of Vienna. She co-authored a book in French with
René Maublanc, on blindness. Using her fluency in European languages, she worked as a translator at the First International Conference for the Blind in New York in 1931, sponsored by the
American Foundation for the Blind. Also in 1931, she also worked with the
League of Nations in Geneva, for the International Bureau of Labor, on immigration issues. ==Personal life==