Unexpectedly heard about editor’s girl with distinctive hair? (7)
I believe the answer is:
redhead
'girl with distinctive hair?' is the definition.
'unexpectedly heard about editor's' is the wordplay.
'unexpectedly' indicates anagramming the letters.
'about' is an insertion indicator.
'editor' becomes 'ed'.
'heard' with letters rearranged gives 'rhead'.
'rhead' enclosing 'ed' is 'REDHEAD'.
(Other definitions for redhead that I've seen before include "Blue Australian" , "Person with carroty hair" , "One with auburn hair" , "Bluey" , "Add here (anag)" .)