All that can presently (May 2025) be gleaned about Elizabeth Otto from sheet music covers and by Internet searching is that she was presumably an American actress/singer who partnered with Katherine Nelson and has been featured on just 2 works published between 1909 and 1911.
Keith-Albee managers' report book ( December 28, 1908 - October 18, 1909 - Page 138a) reports:
Time 18. Pleasingly untheatrical, very much of the "swell, elegant parlor grand" variety. The pianiste is excellent and scores heavily in two classical solos and some comedy instrumental imitations. The comedienne has personality, sings with vim and has certain unique ways. Big hit.
Their portrait on the left is taken from Don't Put Out the Light (1911) music by Irving Berlin, words by Edgar Leslie and published by Maurice Shapiro Music Publisher, New York, USA.
Surfers are welcome to contribute any further information about these performers.