Amayo 天代 looks more like a typical Japanese girl's name than Amaya. -Yo (代 or 世) is a common female suffix, and my Japanese first names database includes both 天代 and 天世 (but not 雨代, nor any other spellings with 雨).
There are two-syllable girl's names ending with -ya (e.g. Aya, Miya), but a three-syllable name ending with -ya is much more likely to be male: Tomoya, Nobuya, etc.
This message was edited 5/13/2019, 3:51 PM