From Japanese 香 (ka) meaning "incense, perfume" or 果 (ka) meaning "fruit, reward" combined with Japanese 耶 (ya), a phonetic character. Kaya was used in Japan for girls as early as in the Edo Period (starting in the 1600s), usually spelled in Hiragana.
Short form of Kaya'aton'my', a name invented for the Native American girl of the Nimíipuu or Nez Percé tribe in the American Girl series of dolls, accompanied by books. The doll was the eighth historical character in the series and released together with the book in 2002.It was made clear by the creators that in reality a Nez Percé girl wouldn't shorten her name, however it was used in this manner to make it easier for younger readers.