Singer Simone (4)
'singer simone' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for nina that I've seen before include "One of Columbus's ships in 1492; girl's name" , "Al Hirschfeld's 'hidden' daughter" , "hidden crossword message" , "- - Simone, 1933-2003, singer" , "- Simone, US singer" .)
(Another definition for ina that I've seen is " Girl".)