The Collaborative International Dictionary of English v.0.48:
Executrix \Ex*ec"u*trix\, n. [LL.] (Law) A woman exercising the functions of an executor. [1913 Webster]WordNet (r) 3.0 (2006):
executrix n 1: a woman executorBouvier's Law Dictionary, Revised 6th Ed (1856):
EXECUTRIX, A woman who has been appointed by. will to execute such will or testament. See Executor.