Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
admĭnistra, ae, f. [administer], a female servant, assistant, or helper, a handmaid.
Lit. and fig.: “Camillam qui glossemata interpretati dixerunt administram,” Varr. L. L. 7, § 34 Müll.: multae sunt artes eximiae hujus administrae comitesque virtutis, Cic. Imp. Pomp. 13, 36.