Aspen is all vegetation and
Ainsley is meh. Which leaves
Aubrey. I like it for a boy, in a vague kind of way - I taught a boy once whose nn was
Aubrey, and I can't think what his real name was. As far as I know, it hasn't been used for girls in South
Africa yet; I've certainly never seen a reference to one. But, we don't keep the right kind of stats, so I dunno really.
IRL, I'd be more likely to use
Auberon than
Aubrey, for what that's worth!