Think it's a major role? Black Haired girl?
Her Website - http://katytownsend.net/about/
Demo Reel - http://www.youtube.com/watch?v=tgFUIV-Licg
Last October (2013), the first English Voice Actor (Jay Preston) was revealed.
Imdb now lists Olivia Hack and Greg Berg as English voices too. Greg Berg has been listed for weeks, so he's #2, not Katy. Roles for Greg Berg as listed as "Gregory, Elegant Gentleman, Impudent Tourist". (A couple sites list him as a voice actor for Lighting Returns so I don't know what the source of the confusion is for him.)
There is a named NPC named Gregory in Lightning Returns. I guess we can scratch him off the list.