Sister of Zsa Zsa (3)
I believe the answer is:
eva
'sister of zsa zsa' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for eva that I've seen before include "Girl's name; extravehicular activity (abbreviation)" , "Braun, Brick or Peron" , "Girl's name; space walk" , "Woman" , "Maria -- Duarte De Peron" .)