Girls marriage rights?

Salam everyone. I will come directly to the point. I want to know that what are the girls right in islam if girl wants to marry a muslim person of her own choice. But parents are not accepting her decision. Without any reason. That person has respectfully send his parents and asked for their daughters hand but they did not agree. Now trying to convince her parents she waited for 2 years. Now the question is that she is on her own now as muslim a girl needs WALI but in her case no one is there for her help. So in that case can she marry that person without wali or making someone else her wali? (not from her family ofcourse as they are against it). She tried her best to convince them but they are refusing just beacuse its her choice and they dont consider it good that girl choose her partner. So please enlighten me in this case that what can she do?