Situation report supporting the girl (7)
I believe the answer is:
shebang
'situation' is the definition.
(shebang can mean any general thing or situation)
'report supporting the girl' is the wordplay.
'report' becomes 'bang' (I've seen this before).
'supporting' is a charade indicator (letters next to each other) (in a down clue, some letters go below others).
'the girl' becomes 'she'.
'bang' after 'she' is 'SHEBANG'.
(Other definitions for shebang that I've seen before include "circumstances" , "Entire operation" , "Lot" , "(Whole) kit and caboodle" , "affair in America" .)