She was regularly featured in Pastor's company in New York and on tour for months after her debut, and also danced in this period for producer John Stetson at the Howard Athenaeum, the leading variety hall in Boston.

A typical billing for Kitty from a Comique playbill in the Harrigan era read: "Acknowledged by the Press and Public to be the only Female Jig Dancer extant, all others are mere imitators and their futile efforts when compared with Miss O'Neil's artistic abilities fall below mediocrity.

[10] O'Neil's dance costume in her early years on stage, as seen in the carte de visite photo above, was virtually identical to that of her male contemporaries.

As dance historian April F. Masten noted: “…rather than donning the flesh-colored tights of female chorus dancers, which suggested nudity, she sports the white stockings, black pumps, and long-sleeved blouse of her male cohort, which signified skill.”[11] As Harrigan moved away from variety to produce his own full-length plays, O'Neil worked more often for Tony Pastor and other variety producers in New York and Boston, as well as on tours of smaller cities.

[12] In 1873, Kitty O'Neil married Ed Power who, with song-and-dance man Frank Kerns, kept a saloon catering to the theatrical profession at the corner of Crosby and Prince Streets in lower Manhattan.

Power died of tuberculosis in 1878, after which Kitty married Harry Kernell, a Philadelphia-born comedian who, together with his brother John, was another celebrated Pastor trouper.

In the 1970s, Donegal-born fiddler Tommy Peoples came across "Kitty O'Neil's Champion" in 1000 Fiddle Tunes and began playing it in stage performances, recording it in 1982 on his LP The Iron Man.