Nevena is interesting. But I'm not sure how to pronounce it. Are you saying, "neh-VEE-nuh" or "neh-VAY-nuh," or some other way? They all sound pretty to me, I just want to make sure.
By the way, I adore
Niamh ("neev") and would use it for a dd tomorrow. It's my #1 name for a girl. You can use anything for a nn. But it would make more sense to me to spell it
Neve as a nn for
Nevena.