It depends on how her name is pronounced in English. If it's pronounced "AH-va," I would write it as in the link l'electeur offered: . If it's pronounced "EH-va," I would write it:
In general, translation requests are out of the scope of this forum, but yesterday I was wondering how to write "Laertes" in Katakana, and it turns out there are a bunch of different ways, which I thought was interesting.
Addendum: While is a common transliteration, I agree with Ben below that is more faithful.