Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Hypermnestra, ae, and Hy-permnestrē, ēs (and mutilated Hy-permestra, Hyg. Fab. 168; Serv. ad Verg. A. 10, 497; Prop. 5, 7, 63 Müll.; like Clytemestra for Clytaemnestra), f., = Ὑπερμνήστρη, the youngest of the daughters of Danăus, the only one who preserved her husband’s life, Ov. H. 14, 1 sq.; Prop. 4 (5), 7, 63.