All that can presently (December 2022) be gleaned about
Nellie Follis 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 in 1909.
Her portrait on the left is taken from
Under the Oriental Moon (1909) music by
Max Hoffmann, words by Harry Williams and published by
The Rogers Bros Music Pub. Co., New York, USA.
Surfers are welcome to contribute any further information about this performer.