All that can presently (December 2022) be gleaned about Marguerite Sylva from sheet music covers and by Internet searching is that she was presumably an American actress/singer who has been featured on just one work namely After All (1919) music by Lee S. Roberts, words by J. Will Callahan and published by Jerome H. Remick & Co., New York & Detroit, USA
Her portrait on the left is taken from the same item.
Surfers are welcome to contribute any further information about this performer.