The Collaborative International Dictionary of English v.0.48:

Shepherdess \Shep"herd*ess\, n.
   A woman who tends sheep; hence, a rural lass.
   [1913 Webster]

         She put herself into the garb of a shepherdess. --Sir
                                                  P. Sidney.
   [1913 Webster]

WordNet (r) 3.0 (2006):

shepherdess
    n 1: a woman shepherd