Jada is OK for a girl, as a form of
Jade. Seems a little trendy and insubstantial to me, but it's alright.
On the other hand,
Jada's also a male Biblical name (1 Chron. 2:28 & 1 Chron. 2:32), as is Jadah (1 Chron. 9:42), so beware.
Jada Eleni flows well, and the styles mesh alright to me.