I adore both
Eugenia and
Jean. I first heard
Ena "EE-na" used as a Scottish-Gaelic form of
Helen (although I can't confirm that's accurate.)
Love it too.
Tough call. I'd probably tend toward
Ena because it *looks* more nn-y. Just because I'm bored here at work, how about other nns like:
Eugie,
Genie,
Jeanie,
Jenny, Genia,
Gigi,
Nina?