All that can presently (April 2022) be gleaned about Isabelle Powell
from sheet music covers and by Internet searching is that
she was presumably an American actress/singer who has been featured on 3 works published in 1904.
Her portrait on the left is taken from Isabelle
(1904) music by J. Richard Tragman
, words by Charles H Lynch and published by The American Advance Music Co.
Surfers are welcome to contribute any further information about this performer.