A lime squash for a girl (6)
I believe the answer is:
amelia
'girl' is the definition.
'a lime squash for a' is the wordplay.
'squash' indicates an anagram (I've seen this in other clues).
'for' is a charade indicator (letters next to each other).
'lime' anagrammed gives 'meli'.
'a'+'meli'+'a'='AMELIA'
(Other definitions for amelia that I've seen before include "-- Earhart, flyer" , "Legless condition" , "-- Earhart, aviator" , "Bloomer maybe" , "-- Earhart, US aviation pioneer" .)