I pronounce it like [name_f]Eve[/name_f] with an N in front. The same as I would pronounce [name_f]Niamh[/name_f].
[name_f]Neve[/name_f] is not my style, but I like it. I have a little cousin [name_f]Neve[/name_f] and she is very sweet.
I have actually never met a [name_f]Nevaeh[/name_f] and not sure what nicknames they are generally given, but I wouldn’t instinctively call a [name_f]Nevaeh[/name_f] ‘[name_f]Neve[/name_f]’.