^^ I'm pretty sure she is, I saw a YouTube Short about the anime, and the speaker mentioned she was 18, but that's just one source, so it's best not to quote me on it :). Also, watch episode 3, the ending hug was really cute and passionate. ^_^
^
They have a charming chemistry of a couple that has one likes being annoy to the other but still have each other back in the end.
Aya is also someone who quite down to earth all thing considers and not being a god or someone with some grand powers but she does care.