I toyed with Eowyn for a while, because I LOVED the character. But I decided that would be too much to saddle on a poor child. And we looked up Arwen and found out it was an actual name, not something that Tolkien made up, which fulfilled Dh's requirements for a name.
Eowyn seems like a real name too, maybe Welsh? Or do you know that he made it up? It can be difficult to tell, as there are so many "real" names that I just am not familiar with.
I think it's much easier for girls to have less common names. There are so many pretty words that can be turned into names. But boys don't want "pretty" names, so it is more challenging.
DS '04 "Boogaboo"
DD '08 "Lilybear"