I am a resident in the United States of America since a long time and I discovered some matters that the Muslims are doing, and which require a sound Islamic ruling, and need to be made known to the Ummah for the benefit of everybody InshaAllah.
One of these matters is concerning the Wali (guardian) of a Muslim woman. This is a matter which is widespread especially among the sisters who embraced Islam and who do not belong to Muslim families.
It is natural for a sister to rely on Allah, the Most High, and then on sisters of her religion, and to find in Muslims a larger family for her and a righteous substitute which is better than what she used to have(as family and relations) before embracing Islam. But what is happening is that many sisters choose a Wali (guardian) for her self. This Wali (and here I presume good intentions, as the prophet said:" Actions are indeed by intentions" so he linked a good intention with a righteous deed- can get married with one of these sisters or with all of them if he wishes, and this is really happening.
So the sister seeks the advice of this Wali in private and public matters in fulfilling her needs.
Is this permissible? What are the conditions and Islamic jurisprudence requirements and principles for this matter? I am waiting for your Fatwa and.
Note: your answer in Arabic, English and Spanish is greatly appreciated as this will be for the benefit of the general Muslims and an additional weight to your good deeds on the Day of Judgment.

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.

Indeed the question comprised several matters:

1. That a Muslim woman in America, if she belongs to a non-Muslim family, she chooses a Wali (guardian) to whom she refers when seeking advice in matters pertaining to religion.

2. That this Wali be her guardian when she gets married.

3. That it is permissible for this Wali to marry her if he so wishes.

4. That this Wali has the right to get married to the women who are under his guardianship.

The answer to all these matters is as follows:

1. In relation to the first matter, there is no harm for a woman to rely on whomever she trusts concerning her religion, if that man is a righteous and wise person, so she may consult him in her personal and public matters.

There is a condition for the above, if he is not a Mahram to her, he should not stay in seclusion with her. Al Bukhari and Muslim reported that Ibn ‘Abbas narrated that the prophet said: “A man should not be alone with a woman except in the presence of one of her Mahrams.”

He should not touch her, see what is forbidden for him to see from her, and these consultations should not lead to anything that is forbidden.

2. Regarding the second point: It is the Wali of the Muslim woman who should conclude her marriage if he is a Muslim. If she has no Wali, or her Wali is a Kaafir (non-Muslim), then it is the Muslim ruler or his deputy who should be her Wali. If there is none, then any ordinary Muslim man she chooses can act as her Wali.

Ibn Qudamah said in Al Mughni: “If a Muslim woman has no guardian and there is no Muslim ruler, then there is evidence which proves that Imaam Ahmad is of the opinion that a just and trustworthy Muslim man may marry her off with her permission.” [End of quote].”

Therefore, there is no harm for this woman to be married through whomever she wants to be her Wali, if, in principle, she has no Wali and there is no Muslim ruler.

3. Third point: whether it is possible for this Wali to get married with her, this is permissible. Al Bukhari reported that Abdul Rahman Ibn Awf, get married with Um Hakeem Bint Al Qarid when she chose him as her Wali.

This is the point of view of the Maliki and Hanafi school of thought and a large number of the people of knowledge. The author of 'Al Hidayah' said: “If the woman agrees to get married to a man, and he concludes the marriage in front of two witnesses; then this is permissible.”

But it is more appropriate in this case to appoint someone else to marry her off to him, to be on the safe side, as some scholars say that it is not permissible that he concludes the marriage contract himself.

Ibn Qudamah said in Al Mughni: “If a man wants to get married with a woman of whom he is a Wali, he has to put her matter in the hands of another man so that he will marry her off to him by her permission.”

4. Regarding the fourth matter, whether it is permissible for this Wali to marry whomever had chosen him as a Wali, it is permissible on the condition that the woman agrees to marry him, that he does not marry more than four wives, and that he deals justly between them.

Allah Says (what means): {And if you fear that you will not deal justly with the orphan girls, then marry those that please you of [other] women, two or three or four. But if you fear that you will not be just, then [marry only] one.} [Quran 4:3]

This is on the condition that there should be no other marriage impediments.

Allah knows best.