Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Neptūnīnē, ēs, f. [Neptunus], a daughter or granddaughter of Neptune: tene Thetis tenuit pulcherrima Neptunine, i. e. the daughter of Nereus, a son of Neptune, Cat. 64, 28; cf. Prisc. p. 585 P.