Two obstacles before a girl (7)
I believe the answer is:
barbara
'girl' is the definition.
'two obstacles before a' is the wordplay.
'two obstacles' can mean two replacements for 'obstacle'.
'obstacle' becomes 'bar' (bar can mean an obstacle or blockage).
'obstacle' becomes 'bar' (bar can mean an obstacle or blockage).
'before' says to put letters next to each other.
'bar'+'bar'+'a'='BARBARA'
(Other definitions for barbara that I've seen before include "Major --, play by Shaw" , "Castle, perhaps" , "Major -, (G. B. Shaw)" , "-- Hepworth, sculptor" , "female officer in SA" .)