This is an circumstantial case that must be looked at individually. Why is the father refusing? Under what pretense?
It would all come down to negotiation and finding ways of making sure the parents are content. Yes, she is an adult, and she could even be allowed to marry lawfully without her father's consent, but as Muslims we strive towards keeping our parents happy.
If after negotiation, and intervention from family and elders to convince the father, he is still adamant about his refusal, and it is unwarranted, that is when it would be advisable to involve your scholar.
We must always remember if we misuse any authority given to us, we will become oppressors and our punishment will be severe.
And Allah knows best.