John Major in his My Old Man writes of Kate Harley:

Kate Harley was billed in 1863 as "The Best Serio-Comic Singer of the Day". Unlike Ada Lundberg she was short, stocky and unprepossessing, and sang some numbers in male dress. Two of these, "Granny Snow" and "Away Down Holborn Hill", were big hits for her. In June 1866 a reviewer was smitten:
"Few can compete with her refinement in style but it is to her undoubted histrionic abilities that her success is principally due."
Her clever impersonations were well received at the Tyne Concert Hall, Newcastle, and she later toured with Vance's Varieties for three years. It may be that her relative anonymity today results from her performing outside London, but there can be no doubt of her popularity and talent.
Of interest is the sheet music The Dark Girl Dressed in Blue arranged by Harry Clifton from a Traditional tune which was performed by himself as well as Kate Harley and George Leybourne.

This list is derived from information provided by Monologues.co.uk which went down sometime in 2023.
The loss of this valuable resource is very sad and a mystery.