From the experts:
Elowen is a lovely nature name from Cornwell that can be used for girls or boys. Not heard much before the twentieth century, when the Cornish language was revived, it blends well with the Welsh 'wen'-ending names and the trendy El-beginning names, and has a pleasant, evocative sound. Pronunciation, however, can get a bit dicey, with most English speakers saying it as the three letters, L-O-N, with a similar emphasis to Eleanor, while Welsh people might put the emphasis on the middle syllable, more like Aloha.
Elowen does not have the long history of other Cornish names: it was officially recognized under the European charter as recently as 2002.
Some other distinctive Cornish names for girls: Ailla, Cordelia, Gwenifer, Jenifry, Kerenza, Talwyn, Tamsyn.