All that can presently (July 2023) be gleaned about The Ramsey Sisters
from sheet music covers and by Internet searching is that they were presumably American actress/singers who have been featured on been featured on just one work namely Alexander's Ragtime Band - Song
(1911) words & music by Irving Berlin
, and published by Ted Snyder Music Co.
, New York, USA
Their portrait on the left is taken from that same work.
Surfers are welcome to contribute any further information about these performers.