A girl's made to go off (for disagreeing with the ref?) (7)
I believe the answer is:
dissent
'go off for disagreeing with the ref?' is the definition.
I can't judge whether this definition defines the answer.
'a girl's made' is the wordplay.
'a girl's' becomes 'dis' (Di is short for Diana).
'made' becomes 'sent' (I can't explain this - if you can you should give a lot more credence to this answer).
'dis'+'sent'='DISSENT'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for dissent that I've seen before include "Opposition" , "Express disagreement" , "Express a different opinion" , "Objection" , "Differ" .)