Unknown outside of this single verse (omans 16:6). She had "laboured much among" the Roman Church, hence St. Paul's salutation to her. It is only a conjecture that she is the same as the mother of John Mark.
The Catholic Encyclopedia, Volume IX. Published 1910. New York: Robert Appleton Company. Nihil Obstat, October 1, 1910. Remy Lafort, Censor. Imprimatur. +John M. Farley, Archbishop of New York