Giving a lime squash to a girl (6)
I believe the answer is:
amelia
'girl' is the definition.
'giving a lime squash to a' is the wordplay.
'giving' means one lot of letters go next to another.
'squash' indicates anagramming the letters (I've seen this in other clues).
'to' means one lot of letters go next to another.
'lime' anagrammed gives 'meli'.
'a' next to 'meli' is 'ameli'.
'ameli'+'a'='AMELIA'
(Other definitions for amelia that I've seen before include "-- Earhart, aviator" , "famous pilot" , "Legless condition" , "Fielding novel" , "Bloomer maybe" .)