All that can presently (December 2022) be gleaned about
May A. Bell-Marks from sheet music covers and by Internet searching is that she was presumably an American actress/singer who has been featured on 2 works published between 1899 and 1901.
Her portrait on the left is taken from
Stay in Your Own Backyard (1899) music by
Lyn Udall, words by Karl Kennett and published by
M. Witmark and Sons, New York, Chicago, San Francisco, USA.
Surfers are welcome to contribute any further information about this performer.