A girl from Stevenage (3)
I believe the answer is:
eve
'a girl' is the definition.
'from stevenage' is the wordplay.
'from' indicates the answer is hidden within the clue.
'EVE' is hidden within 'stevenage'.
(Other definitions for eve that I've seen before include "Threshold" , "Lady first appearing" , "The night before a festival" , "First lady from the night before" , "Previous day" .)