Well, I thought (I'm not Welsh so I'm not completely sure) that
Adara is also a Welsh name (I have seen it as a name used for girls, but now my question is if it is a unisex name), meaning "cathes birds". I have seen this on quite a few sites actually.
I also found Avaon on those sites, as a Welsh male name. I have never seen the name Afaon before, only Afan or
Afon.
I wasn't quite sure about your question of me reading sci-fi novels. What do you mean?