One's label confused a girl (8)
I believe the answer is:
isabella
'girl' is the definition.
(I've seen this before)
'one's label confused a' is the wordplay.
'one's' becomes 'is' (roman numeral).
'confused' indicates anagramming the letters.
'label' is an anagram of 'abell'.
'is'+'abell'+'a'='ISABELLA'
(Other definitions for isabella that I've seen before include "sludgy colour" , "drab colour" , "Bails Lea out for the name" , "Wife of Ferdinand V" , "Henry VIII's first mother-in-law" .)