All that can presently (March 2021) be gleaned about Mabel Stanley
from sheet music covers and by Internet searching is that she has been featured on on just one work namely The Rector's Daughter Nell
(1888) words & music by Gussie Lord Davis
and published by T.B. Harms & Co.
, New York, USA.
Surfers are welcome to contribute any further information about this performer.