Circa 304 A.D. Feast Day: January 23.

"Martyr of Rome, in some traditions the foster sister of St. Agnes, stoned to death when discovered praying at Agnes’ grave. Emerentiana was possibly
martyred elsewhere. Her cult was confined to local calendars in 1969 ..." ( source: Catholic Online http://www.catholic.org/saints/saint.php?saint_id=3109 )