Yeah I can see that. The only thing is the wen seems masculine and the wyn to makes it more feminine. So maybe Elowyn??
Elowen is feminine (http://www.behindthename.com/name/elowen).
However, Bronwen (a Welsh name) can be spelled Bronwen or Bronwyn and both are feminine. If you insist on changing the spelling to something that you feel in a foreign name is more feminine (which I think is really unnecessary) at least it's not like it's never been done before.
However, I'd leave it as Elowen.