Lona, Sophia, Inger, Olga and Gertrude Barrison were actual sisters (many "sister" acts in Vaudeville were not) of Danish or Danish American descent. They were said to sing in high squeaky voices, and dance with middling ability. They achieved notoriety, however, by ingenious use of double-entendres and carefully pushing the envelope of what was allowed on stage.
In their most famous act, the sisters would dance, raising their skirts slightly above their knees, and ask the audience "Would you like to see my pussy?" When they had coaxed the audience into an enthusiastic response, they would raise up their skirts, revealing that each sister was wearing underwear of their own manufacture which had a live kitten secured over the crotch.
A similar act was later performed by the Machinson Sisters.
The Barrison Sisters were advertised as The Wickedest Girls In the World.