Girl a shade upset by fib (7)
I believe the answer is:
natalie
'girl' is the definition.
(girl's name)
'a shade upset by fib' is the wordplay.
'shade' becomes 'tan' (I have seen 'Shade of brown' mean 'tan' so perhaps 'shade' could also mean 'tan').
'upset' says the letters should be written backwards.
'by' is a charade indicator (letters next to each other).
'fib' becomes 'lie' (I've seen this before).
'tan' back-to-front is 'nat'.
'a' put after 'nat' is 'nata'.
'nata'+'lie'='NATALIE'
(Other definitions for natalie that I've seen before include "Girl's name" , "Wood perhaps" , "female name" , "girl" .)