Wali of Muslimah if her parents are kuffaar
Question

I come from a muslim family and was brought up with Islamic faith. Although, I have been through a stage in my life which I call the "dark stage" of my life, in which I was involved with "jahiliyah" practices for some years (yes, those irresponsible and sinful acts). Allah has blessed me with guidance and brought me to His straight path again. Since that time, I have been having a relationship with a christian girlfriend, who has accepted Islam just recently, by Allah's will. We plan to be wedded soon after we are settled. One problem is that she comes from a devout Christian family, not to mention her father being a christian priest. Ever since her family found out about our involvement, they have tried almost everything to part us, we haven't told them about my girlfriend's conversion though. Right now, our relationship has reached a point where she is willing to oppose her family and runaway from them eventually. Even though we know it will be hard to go through, my girlfriend and I really love each other. As I understand, the Islamic law requires that in marriage, a woman should be accompanied by a "wali", which to my knowledge, should come from her family. My first question, can our plan to marry without her family's consent be in accordance with Islamic law?
And second, if it can, who can be her "wali?", since not one of her family member agree with our relationship.
Thank you, assalaammu'alaikum.
Praise be to Allah.First, I offer thanks to Allaah for his grace in having guided you to the path of truth after experiencing a dark journey through 'jahiliyyah', a journey into ignorance and meaninglessness. Allaah guides to his truth whomever he wills. At this point of your life, as an expression of gratitude for Allaah's blessing, you should carry out your duties towards him and desist from the actions that gain his wrath. In fact, Allaah, at this point in your life, must take priority over everything else. You further ought to make up for what you missed in the previous part of your life, to double your efforts in performing worship and to haste in doing good deeds.
Secondly, since this lady in question has converted to Islam, thanks to Allaah, none of her kaafir family members can act as a guardian (wali) of her interests; no kaafir can act in this capacity over a Muslim. If there is a Muslim with some authority in your area over the affairs of the Muslim community, then he can act in this capacity, based on the Prophet's (peace be upon him) hadeeth:
"No marriage contract can be concluded without the presence of a Wali. A Sultan (authority figure) can act as a Wali for those without one." (see Ibn Majah and Imam Ahmad, Hadith number 1880; also in Salih al-Jaami', hadeeth number 7556.)
If there is no authoritative Muslim person, then one should refer to the community Muslim leader or any Muslim who is just ('aadil), respected, and of high character, such as the director of the Islamic center or its imam, to conclude the marriage contract of this sister, with her consent.