Girl's perfume reportedly causing a difference of opinion (7)
I believe the answer is:
dissent
'a difference of opinion' is the definition.
(I've seen this before)
'girl's perfume reportedly' is the wordplay.
'girl's' becomes 'dis'.
'perfume' becomes 'scent' ('scent' can be a synonym of 'perfume').
'reportedly' indicates a 'sounds like' (homophone) clue.
'scent' is a homophone of 'sent'.
'dis'+'sent'='DISSENT'
'causing' acts as a link.
(Other definitions for dissent that I've seen before include "Dispute" , "Object" , "Difference of opinion - snidest (anag)" , "Express a different opinion" , "Raise objections" .)