Is it permissible for a Muslim girl to marry recently without her guardian's consent, due to her father's rejection of her Islam, knowing that she is not yet 21 years old, and how long do the procedures for declaring Islam take?

Praise be to Allah, who has blessed this sister with guidance to Islam. We ask Allah to grant her steadfastness upon it, and we advise her to be diligent in seeking beneficial knowledge and performing righteous deeds, and to associate with righteous Muslim women. We ask Allah the Almighty to reward you for being instrumental in her guidance. Know that the customary public declaration of Islam today is not a condition for its validity, nor for the validity of marriage to her. The declaration is subject to what serves the best interest. The declaration of Islam does not require lengthy procedures. A wali (guardian) is a condition for the validity of marriage. If the girl does not have a Muslim wali to marry her off, the Sharia (definition) judge performs the marriage. In the absence of a Sharia judge, she should appoint a trustworthy Muslim man.