All that can presently (October 2023) be gleaned about
Jennie Morgan 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 between 1877 and 1880.
The cover of,
The Beauty of Limerick (1880) music by
David Braham, words by Edward Harrigan and published by
Wm. A. Pond & Co., New York, USA, states that she sang this song in Harrigan and Hart's
Theatre Comique in New York. Brief playbill and newspaper cuttings describe her as performing artistic renderings of pupular songs and ballads.
Surfers are welcome to contribute any further information about this performer.