Girl develops clothes (3)
I believe the answer is:
eve
'girl' is the definition.
'develops clothes' is the wordplay.
'clothes' indicates the answer is hidden within the clue (the letters clothe the hidden word).
'EVE' is hidden within 'develops'.
(Other definitions for eve that I've seen before include "Period immediately before" , "Adam's wife" , "First mate" , "'All About - - ' (Bette Davis film)" , "Night before an event" .)