Do you mean the original Latin feminine forms? Because that would be like asking for the English feminine form of Smith
, Jones or Robinson.
No such animal!Nerina
, to my knowledge, has the same meaning as Marina
. A consignment of flower bulbs was being sent from South Africa
to Europe in, I think, the 19th century when it was shipwrecked and some of its cargo was washed up on the Channel Islands. A particularly lovely lily got the name Nerina
and for a long time was thought to be a native of Jersey; then it was rediscovered here and history got rewritten. So I don't see a direct link to Nero
, unless his name had a Greek origin; which seems unlikely.
But there's nothing to stop you, or anyone, from inventing modern fem forms of these names if you'd like to.