Answered by Ustadha Umm Abdullah
When one has been appointed a wali for a female convert what then becomes the etiquette of interaction as one would have guardianship over a woman with whom one is not blood-related? If the prospect of marriage ever came between a wali and his ward, would a new wali have to be appointed for the marriage transaction?
In the name of Allah Most Merciful Most Compassionate
I pray you are well and in the best of health and iman.
“The Bride’s guardian:
If the bride has no Muslim guardian and there is no Islamic magistrate to act as one, she may authorize a male Muslim who has the qualifications of an Islamic judge, or if there is none, then a male Muslim who is legally upright to act as her guardian in marrying her to the groom”
(The Reliance Of the Traveler.Sh.N.keller. p 519)
The guardian is appointed just for the mission of conducting the marriage. His guardianship does not imply that he may interact with her as her close relatives do. Rather, she is considered a complete stranger to him.
If she chooses to marry the guardian, then another guardian should be appointed, though that first guardian shouldn’t have been appointed in the first place if there was a prospect of marriage to the woman!