The Collaborative International Dictionary of English v.0.48:

Jewess \Jew"ess\, n., fem. of Jew.
   A female Jew; a Hebrew woman; a female adherent of Judaism.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

Jewess
    n 1: a woman who is a Jew

Easton's 1897 Bible Dictionary:

Jewess
   a woman of Hebrew birth, as Eunice, the mother of Timothy (Acts
   16:1; 2 Tim. 1:5), and Drusilla (Acts 24:24), wife of Felix, and
   daughter of Herod Agrippa I.