This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
姷 combines 女 (woman) with 有, which likely contributes the sound. The exact historical development is uncertain.
A woman 女 beside 有, a shape associated with having or existing. Without a clear meaning, picture a woman holding something, but the exact idea is uncertain.
For ユウ, imagine a woman named Yuu standing beside the 有 component: Yuu -> ユウ.