All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
First of all, we want to draw the questioner’s attention to the fact that friendship between a man and a woman, a girl and a boy, is illegal in Islam due to many huge evils resulting from this friendship. A girl should not insist to marry a person if her father is not content to do so. Certainly the father has a better vision in this concern. No one knows where the good lies. Allah Says (what means): {…and it may be that you like a thing which is bad for you. Allah knows but you do not know.} [Quran 2:216]
She should ask Almighty Allah to help her choose a pious man. It is forbidden for her to marry without the approval of her guardian. The Prophet said: “Nikah (marriage) is invalid except with the consent of a guardian.” At the same time, it is prohibited for a father to prevent his daughter from marrying a good suitable man. The Prophet said: “If a man whose religion and moral character are pleasing proposes to marry your daughter, then marry her off to him. If you do not do so there will be corruption and great evil on the earth.” [Abu Daawood and an-Nasaa-i] The best thing for this girl is to be satisfied with her father’s choice, if the father is pious and reasonable.
Allah knows best.